Obviously most beastmasters must have a character age of <15
Apparently! lol
A pet feature should definitely be spotlight heavy.
Otherwise the pet - per definition - is too frail/weak to fulfill its role.
The problem is that the design must acknowledge that any pet feature worth having must abandon any hope of being spotlight neutral.
Any effort that attempts to keep the pet spotlight neutral fails to understand the inherent need of an animal companion function:
That the player wishes to play TWO characters, neither of which is so frail/powerless as to be a weak link or liability to the party.
I haven't come across many players that want the Beast taking up a lot of spotlight. They, IME, don't want two full characters, they want a character with a useful pet. In 5e, that either requires houserules (for a combat pet), using hireling rules with a beast (kludgey and weird), or taking a feat or a level of wizard to get find familiar (useful scout pet).
They want their class feature/pet to survive combat, without taking as much (much less more) spotlight as the actual character. Which is absolutely doable. Being harder to kill doesn't mean more spotlight. Surviving a fireball doesn't put the spotlight on the creature.
I would prefer a ritual which calls a beast within a 20 mile radius to you or which bonds with a beast already present (your choice), and it bonds immediately with you when it arrives. That way you might not get to choose which beast shows up if you don't already have one nearby that you've chosen.
Would you compromise on that being one of two rules options presented in the feature?
Because I know several players for whom that would be a non starter, and they'd just play something else, just like they would if the PHB ranger had no magic.
They aren't playing a BM ranger to play a guy who can quickly befriend new pets each time they get their pet killed, using nearby animals as canon fodder. They're playing to have a lifelong bond with an animal that becomes as a sibling to them, grows with them, and is bonded to them both in terms of the bond one forms with a beloved pet, and magically bonded. I've taken to just making it an hour ritual that costs 10 gold, making it a beast familiar, complete with some communication, but I know that cost is too low for many GMs.
And honestly, if we just made it a familiar that can attack, with even beefier options than the chain warlock (but less magical), I think the feature would work better at all of it's goals. You form a bond with a creature, and as part of that it becomes something more than it was, bonded to you spiritually and magically, able to speak to you, to share it's senses with you, and to come to your aid no matter where you are, returning even from death to fight and explore beside you. It'd be a better exploration feature, and a combat feature that wouldn't be a liability in later levels.
And the "no magic!" crowd can use the rules Mearls is building in Happy Fun Hour to build a pet using spell slots, instead of getting the spellcasting feature.