OB1
Jedi Master
This in itself is impossible, as aside from usability issues (no way to revive the pet easily) one of the big complaints was just that it was a weak class overall. Anything to address this by nature requires the prior iteration to be left in the dust as far as effectiveness goes.
The complaint about power was found to be an illusion. The main problem with the class was feel. As you mention, no way to revive the pet easily. That's correct, in the old version, you had to get a new pet, which takes about the same amount of time as reviving an old pet in the new version, so there is no difference in power, only difference in feel and meeting expectation.
Now, because of the increased power of Natural Explorer, they were able to limit the list of beasts that you have access to, so that you end up with a pet that is made and meant only as a combat helper to the point that the new Ranger looses their personal second attack (and therefor a second use of sharpshooter), whereas in the PHB version, the pet was designed to give additional exploration pilar utility with some combat effectiveness at higher levels. This utility allowed me to use hawks in the forest or spiders in the under dark to scout ahead, find enemies, and set up ambushes for them, giving my party surprise rounds in many a combat, often gaining advantage on top of it where I would unleash a couple of Sharpshooter long bow attacks from a safe distance. I play my Ranger as an Army Ranger with his own personal drone.
But this added utility in the UA Ranger is so good that it also renders half of the Rangers spell list obsolete, with will allow the UA Ranger to focus on picking and casting combat spells that allow the ranger to nova in combat. And this I think is where we get into a fine line discussion about whether that added combat power is about making the Ranger "feel" right, or just catering to "low power" complaints. I can see the argument that this is how the ranger should work, that exploration pillar abilities should be built in with defined, rule based outcomes, leaving spells to primarily increase combat effectiveness.
With that said, I think there is an opportunity for WotC to fix the feel of the Ranger (their stated goal, and the supposed goal of most of the Ranger complaint threads) without giving it a power boost that makes the old Ranger obsolete or the new Ranger the new class power leader.