Hypothetically, let's assume we have Meyers circa 2023, some other decent WRs, and a rookie that Belichick reached for in round 5. The rookie wasn't even invited to the combine, is rated 5.10 on NFL.com's 8 point scale where 5.5-5.6 is a priority UDFA. He's undersized at 5'10"/185, but both fast and quick, and just totally raw. The Pats' draft was graded a C+ by SI, and this rookie wasn't even named as a notable pick. The guy that fits that description, BTW? Tyreek Hill.
Meyers is great, I love the kid. The problem that someone like Meyers brings, especially when he has a tight relationship with the QB, is that he sucks up targets. He gets separation, has reliable hands. On a slant route designed to get 8 yards, you'll complete the pass 80% of the time and get 8 yards. But the kid who isn't getting the chance to run that route would get 70% completions. He'd get 8 yards 30% of the time, 10 yards 30% of the time, 15 yards 5% of the time, and 30+ yards 5% of the time.
"But for" Meyers, Bourne and Thornton would have gotten more reps, and more targets on the reps they got. Ben Coates was great for Bledsoe to have as a rookie, and maybe the next year or so. But after that he probably stunted Bledsoe's development, because he gave Bledsoe easy outs. If they trade for Hopkins, he's redundant. If they trade for Jeudy, you don't want Meyers stunting the development of that relationship with Mac, and you don't want him taking targets away from Jeudy. If you draft a WR1 this year, chances are it's a slot/quick guy, who would be competing directly against Meyers for snaps.
The Patriots have some very nice options at WR2/3/4. Bourne has barely scratched his potential - 2021 was closer to what I'd expect from him. Thornton is just learning to play the pro game, but can change a defense.
The reason the Patriots' offense under Brady worked wasn't just because they could roll up first downs, but because the people that they used to do it - Gronk, Edelman, etc. had the potential to pop a short gain into a big play at any time, and punished a defense both physically and mentally - any mistake in coverage was deadly, and any physical letdown after the catch was costly.
Every snap is an opportunity. Taking the 80% chance of 8 yards is always at the cost of the 90% 3 yard run, the slightly lower percentage of the 8 yards that breaks for more, or the 40% chance of hitting a deep corner. Meyers doesn't tax or exhaust a defense. He doesn't give you the benefit of any upside volatility around the results of the high-percentage passing plays.
If you don't have any upside volatility around the results of the high-percentage passing plays, you have to turn to lower percentage passing plays to try to get your chunk yardage. That was a big part of the problem with the offense in recent years. Bourne, Thornton, Jeudy, Hopkins, Henry getting more targets is a step to solving that. Almost any WR taking those 8 yard slants will provide more upside vol, and many of those will not lose you all that much in completion percentage. But if they don't get their chances, it doesn't matter.