>>48800613If you level up only a single Pokemon, even if you don't grind, then that Pokemon will be pretty high leveled vs everything.
This has pretty much always been the case in Pokemon as a franchise, although dealing with type disadvantages/immunities discouraged playing like this, and depending on what Pokemon you picked, you'd face needing to grind or to power through with a ton of items. Having more Pokemon means you need to train them more, but gives you more options vs dealing with opponents.
If you level up a team of two Pokemon, you'll be a bit lower leveled, but still stronger than average. A team of three, same deal. A team of six, you might even start being behind the curve, especially if you avoid wild Pokemon battles and just stick to mandatory Trainer fights.
The modern exp share lets you focus on one or two Pokemon, except everyone else also gets a free 50% exp out of nowhere.
At the absolute worst, your full team of six is still as strong as if you only ever trained two Pokemon.
