Tl;dr a decent portion of the community of spam fighters went on strike.
Expanded answer
We have extremely good community spam protection. Or, we used to. Normally, there’s a number of tools used to fight spam and get it flagged very quickly 24/7. This means most spam gets deleted extremely quickly.
A number of users (myself included) object to recent actions by SE and are now on strike. As such, when the subset of the community dedicated to fighting spam stops fighting spam, there will be more spam visible. That is ... kinda the point. People notice when less moderation means more garbage (spam). Notably, the strike includes the primary system used for spam fighting.
If SE agrees to the requirements to end the strike, you’ll see less spam. If you’d like to support the strike, consider joining the strike.