Number one reason why Tor is dead is Cloudflare.
Let me digress here. In my opinion, Cloudflare does a lot more censoring than all state actors combined, because they singlehandedly decide if the IP you use is "trustworthy" or "not", and if they decided it is not, you're cut off from like half of the Internet, and the only thing you can do is to look for another one. I'd really like if their engineers understood what Orwellian mammoth have they created and resign, but for now they're only bragging without the realization. Or at least if any sane antitrust or comms agency shred their business in pieces.
And Cloudflare by default makes browsing with Tor unusable. Either you're stuck with endless captchas, or you're banned outright.
Number two reason why Tor is dead is all other antifraud protections combined. Try paying with Stripe through Tor. There is quite a big chance you'll get an "unknown error" of sorts on Stripe side. Try to watch Netflix in Tor - exit nodes are banned.
Everyone kept shouting "Tor bad, Tor for criminals", and it became a self-fulfilling prophecy. It's really hard to do just browse web normally in Tor, because all "normal" sites consider it bad. The "wrong" sites, however, who expect Tor visitors...