Maybe back in the 1990s, but modern RPGs aren't nearly this obnoxious. Even then, I don't recall needing to go rest up every 4 random encounters in FF7.
It's not a "learning curve". It's just repetitive, tedious grinding. If there was a learning curve, I could use my knowledge from having previously played this game to speed up my levelling process, or beat bosses even though I'm underlevelled (e.g. like you can in Dark Souls), but that's not how it works.
Grinding can be cut short by advanceing the correct Quests in the right order.
Get a companion, than set your eyes on improveing equipment and learn stuff like Alchemy to start brewing Potions.
Learn Magic, get another companion, each time take your time to buy more equipment for the Party.
Switch from Goblin hunting to Bandit hunting for more Gold.
Try to help the Girls in Weirdwood without leaving the Town in order to become mayor or help Shakalah build her own tribe to get passive income.
keep playing the sharpshooter game a keep requesting Water until you have a minimum of Potions and at best some reserve to craft more once you manage to procure more advanced ingredients (Liandra's story can only advance after getting frisky with her as far as I recall).
The Key is to start the game with many Sidequests and not to focus on a single Character, as with advanced Quests and Story comes harder enemies.
The hardest part is the very Start until you reach a basic Level like 10.
Tinkerer made a Point that you don't play a hero set on a journey to save the World but a Peasant without education or combat training setting out into the world to find his place in Live and get laid.
Beating Bosses while being underleveled is hard and sometimes requires reloading but if you build your Character carefully and have Comanions from other Quests is very much possible.
Does it also happen with Rosy?
Yes it does, Liandras Mother also have that mechanic... maybe the Stepsister, haven't spent enough in game days away to actually check, but since you can give Gifts and help at the farm it's likely