I've tried A21 without jars (vanilla) and with jars (via mods). What I've discovered is that I kinda dislike jars after all, lol.
BUT I also hate the fact that I can build a campfire right next to a lake and somehow cannot get any of that water into a pot for boiling. I'm not complaining about "realism" here. My complaint is that TFP went about the water rebalance in such a hamfisted and clumsy way. It feels like an artificially restrictive change made purely because they couldn't figure out a less over-engineered solution.
The absolute best solution I've found is Silver's water bucket mod. No, it doesn't bring jars back -- jars are unnecessary with this mod. It allows you to scoop murky water with a bucket from a POI and then boil the filled bucket on a campfire. 3 minutes of boiling produces 3 jars of clean water. The bucket mod is balanced, uses existing game assets and mechanics, and allows water collection without ruining the thirst mechanic during the early game. Scooping water slowly depletes the POI water source, boiling the water takes an appropriate amount of time + fuel, and buckets are non-stackable so water hoarding is vastly reduced compared to what was possible with glass jars.
I really don't understand why we ended up with dew collectors when instead the devs could have simply tweaked water buckets to do something that a bucket should be able to do; gather and transport water!