i don't know who this 'most other people' refers to, but i can tell you as someone who has been using multiple anime tracking sites like MyAnimeList and Anime Planet and AniList for a long time that this is quite normal. most of these sites also get similar criticism because most people aren't that active. however, what you fail to realize is that people are generally active, it's just that most people are generally quite passive with the sites being mainly driven forward by a small, core group of people. even here only a small number of people actually contribute regularly to the site. again, tell me when was the last time you did anything meaningful to improve this site?
this site was intended to be a social media style anime/manga tracking website. for that purpose, it succeeds pretty well. i'll refrain from going into the inner workings of this aspect and delve for now into the forums issue. yes, there are many bugs on these forums. one of the most common ones cited was the 'avatar bug' which tends to come after people make a post here in the forums. there were also problems like the 'failure to reply to a particular post' or 'forum activity link taking the user to his own dashboard.' regardless of how many problems there are, the developers are trying their best to fix the issues, so cut them some slack. you probably don't realize how difficult it is to manage and improve a site with a small staff, especially when they, like many other people, have lives of their own too. i for one applaud the developers for budgeting the time and effort for making a great site like this while also constantly trying to improve it for everyone's convenience. one thing you should also note is the fact that the developers announced that they are planning to majorly overhaul the forums this coming weekend. and from what i hear, this is just one of the major changes they are planning atm.
aside from the forum aspect of the site, the developers are also trying to fix some common issues on the main tracking site. examples range from missing/incorrect/misplaced anime database entries to underdeveloped manga pages to something even as simple as 'no tracking on feed posts.' while there are many problems at the moment, they are regularly being addressed along with new added features to appease certain niche groups. there are several topics or interests that could and have been easier to talk about within groups than with the entire community. by sharing common interests, these groups tend to encourage more discussion and activity than the forums did in the past. when looking at my feed, i regularly get a new post from many of my groups every few minutes to few hours. again, this was one of the benefits of the 'improvements' that the developers have been striving to make. when asking around in the forums, i found that many of the developers are/were busy making new changes, so i don't see how this site is not 'active' to say the least.
in regards to the number of users on this site, according to stats given by the developers, there are roughly 90.6k users in total, with only about 18.5k of them being active within the last 30 days. if you ask me, that seems relatively active, especially considering the fact that many people use alt accounts and are busy with real life issues. not everyone is generally going to be consistently active here. in fact, many people only come here for the tracking aspect. even you admitted to not coming here in a while. if you look at the forums about page, it says that there were roughly 3k new users within the last month, which is roughly 100 person per day. that is active no matter how you look at it. overall, there is no doubt that this website is anything but not active. so stop it with those 'hummingbird is dying' comments as they are so uncalled for.
you also mentioned something interesting on google traffic. i hate to break it to you but that is not an accurate measure on whether something is good or active. it's just a matter of whether something has been popular or widely visited in a while. if i remember correctly, MAL has been there for several years longer than hummingbird, and as such it should make sense why that is more popular than this site (even though MAL is just cancer-inducing ). rather than complaining about a non-existent problem, why don't you try to help out and contribute to the site more. i've seen many internet reviewers beginning to switch to hummingbird as a way to get more people to come to this site. i've had many associates telling about this site to their close friends and family members. just because this site isn't as active as the time shortly after it got released doesn't automatically make it 'dying.' one noteworthy case is the fact that many old users like 'roriconfan' are slowly returning to this site. no matter how i look at it, it just seems like our userbase is just evermore increasing.
overall, while this site may not be perfect, it suits the needs of me and many other users on this site. with things finally beginning to improve the site as a whole and with more and more people joining this community, i don't see in anyway possible how 'hummingbird activity is dead.'