This. Nobody is making up his stats. He averaged over 1,000 yards per season in his 3 years in San Francisco. That might not seem like a lot but it's pretty impressive when you think about that offense and who was throwing him the ball.
With Crabtree and Vernon Davis on the field I don't think the 49ers planned on Boldin being their leading receiver when they signed him but that's exactly what he did. He led the team in receiving all three years he was there.
I don't think anyone believes that Anquan Boldin would come in and be our #1 WR while putting up Pro Bowl numbers. His days of being a Pro Bowler are over but he doesn't have to be a Pro Bowler to help this team. Even at 35 years old he is still a really solid player and could fill that Colston role IMO, help move the chains and provide another redzone target. Also, apparently he's a world class teammate and human being in general. That would be a bonus considering how young our WRs are.