Every fanbase in the league can say that every summer. But we've had Marquise Goodwin in the division for four years, we know what he is. And if he's your WR2 behind Garcon, then your WRs probably aren't very good. The only way the 49ers WRs will be even reasonably solid is if Pettis is an instant contributor, and relying on a second round rookie to produce right away brings you into uncertainty/hypothetical territory even beyond where the Pats are with stuff like hoping one of Patterson/Dorsett can be a capable WR3.
It's not impossible that the WR depth chart works out fine for them, especially with Shanahan calling the shots, but they have every bit as much uncertainty in production across the depth chart as the Pats do, without the level of established production at 1-2 that the Pats have.
Goodwin looked pretty good last year. He played for the Bills, with Bills QBs, when in our division.
Pettis looks good this year. He will contribute instantly.
Kendrick Bourne is a sleeper, sort of like Garcon was once upon a time.
Trent Taylor contributed as a rookie, and he's awfully solid for what he is.
Richie James was high risk/high reward draft pick because he was coming off an injury. He's played lights out in preseason, and he made the time.
I'm not saying any of these guys are world beaters, but the 49ers have a passing scheme similar to the Pats, in that they utilize every passing option on the field (it helps to have a top 5 QB in the league, which Garoppolo is, in my opinion). This means they all have value and are all useful to the team. It's a deep depth chart, considering. An injury to any of these guys would mostly just mean 'next man up'.
Edit: I rushed to respond to you and missed your second paragraph. I mostly agree, but I think the 49ers have the better WR depth right now because of less injury and suspension issues. The Pats have already cut Jordan Matthew, Kenny Britt, Eric Decker, and Malcolm Mitchell. At least the first two of those were guys that were expected to contribute. When you have to fall back on plan B and C, that can hurt you. The 49ers are still with their Plan A. No reps were wasted in the offseason.
