You can't even do it ironically anymore because the average user doesn't pick up on it and whatever insane joke you pull will become internet norm in the future
I made an account on twitter/x specifically to promote my site at some point. I was shadowbanned by default and had to follow other people, like and share their posts and comment on other's post just to get my own posts to show up on people's feeds. When I checked again at some later point I was shadowbanned again.
When I tried reddit I also noticed that I was shadowbanned by default and didn't even bother to do anything about because I assumed it would turn out the same way. Like I said you can use those sides to get the word out, but only if you're actively using them as a user to begin with.
That's almost a job in itself because you have to constantly make sure not to get shadowbanned. This is probably only an option for people who already use "social media" sites in the first place.
Putting a link to your site in forum signatures was the way to go. Unfortunately, forums are 99% dead.