I have the opposite problem recently where a very common class of spam (usually "you have won") just slips straight into my inbox no matter how many times I flag it. It looks so obviously like spam it's quite shocking it doesn't get picked up.
Ended up switching to my own domain and while there’s still a few places which don’t let me change my email, most things weren’t very difficult to switch over. It did take a long time since I did it organically for the most part.
Fastmail has been absolutely great so far, no complaints. Powerful filter/rule engine, the ability to choose folder or label systems for your mail, a great app but also IMAP/DAV access for inter-compatibility, and tons more. I haven't played around too much with a bunch of the other things it offers (calendar, files, notes, etc) but for mail and contacts, at least, it's been solid.
I have a wildcard setup for vlad.gg so all emails go to my inbox, with specific aliases set up that get auto-labeled using filters. I also have wildcards set up for various other domains and then on a family domain, I have aliases that redirect emails to their own personal inboxes (on Outlook/Hotmail FWIW). All super easy to set up.
At this point, I think Google is just intentionally sabotaging Gmail.