I always think this until I try to play Crystal again. I absolutely adore the art of gen two and the pallete they use is beautiful but my god the grind walls in that game suck. I also am not a fan of the old physical special split which is why I opt for HG/SS over G/S/C but I completely understand replaying them because even though it's a grind I'll do it just for the art and the music.
I don't think there's much of a grind wall, but I see it as more an incentive to use a different playstyle.
You won't be able to brute force certain bosses in crystal. For example, Whitney's Miltank and Clair's Kingdra (Even Chuck's Poliwrath and that super high leveled houndoom in the rocket base) are all examples. It gives more of an incentive to use other strategies rather than brute force. I almost never grind, but have had great success against the bosses. I'll sacrifice one pokemon using flash as many times as possible, another lowering defense, then go in with a physical attacker.
I was about 10 levels below Lance, but was able to beat half his team with a stalling Crobat (Attract + Confuse Ray). Currently have a corsola on my team and it's equally valuable. Part of why these are my favorite games in the series. It encourages uniqueness. I've tried these games with an optimal strong team, and actually found myself struggling more.