Accidental sexy scenes and an oblivious young teen hero has always been in Danmachi. Remember the completely superfluous fanservice river bathing scene in season 1?

I agree with David that your tastes may have simply grown away from anime and the stuff that normally comes with it (i.e. fanservice, asexual heroes, illogical powerups, etc.). Anime in itself didn't change as drastically as you seem to think.