I'm curious, do you use this on mobile or are you talking about a desktop experience?
Personally I find more ads on something like Sync on mobile than I did on Reddit which I can block, but I am now forced to use the Reddit desktop site.
Yeu, sync has ads because the developers of sync put ads into it.
Vanilla lemmy and jerboa certainly dont.
I can imagine some instance admins considering forking lemmy and putting in ads. At the moment, most instances are run as a hobby (for free) or by contributions (ie donations from members).
The development of lemmy was funded by a VC-type thing for a while, not sure if its still active. Otherwise, its also developed thanksnto contributions