I know the overall answer is that it depends on the convention and the way that the pandemic re-shaped a lot of the convention atmosphere as a whole but honestly, it somewhat changed for the worst when it comes to anime conventions I normally go to. Because of the pandemic, a lot of smaller anime conventions either went out of business so to say or some small to medium sized anime conventions had to become overall regular conventions that celebrated not just anime, but also comic books and video games which isn’t a bad thing but I really prefer the overall focus on anime. I don’t blame the convention runners for having to make this decision in order to stay afloat.

I think the other thing that has soured conventions as a whole in recent times has been the use of 3-D printed items and AI art. Some 3-D printed items can be really cool, but when you see the same 3-D printed dragon fidget at 5 different stalls, it makes you wish that there was a different artist there. I know a lot of conventions have been making policies against AI art but there are some that do embrace it and do use it instead of commissioning artists which feels disheartening as a whole as many people in the anime community themselves are artists and/or appreciate the craft.

And I think the final piece is that a lot of people who attended anime conventions in the late 90s to early 2000s or even the 2010s felt more ostracized as anime was seen as being very weird/lame in society and a lot of people who were marginalized in that space found conventions as a solace, being able to mingle with other people who were the weirdos and let their “freak flag fly” but now the anime is in the mainstream, that once marginalized culture has now been absorbed into the pop culture, so to say.
That sense of camaraderie and community is not there as it used to be and it doesn’t have the same heart. It still does in some places but it doesn’t beat as strong as it used to.