Size? Yes, Collins has very nice size. Even 1st round size, though 1st round WRs can come in every size.
Routes? Pretty subjective. Collins does average fewer targets/game than all of the 2021 1st round WRs.
Hands? Only one drop vs. 33 catches. Looks like 1st round hands to me.
Play after catch? His YAC of 4.0 would place him 4th among the 5 WRs selected 1st. But zero broken tackles, which seems low for a receiver of his size.
I would suggest
8 WRs out of the 2021 draft outperformed Collins. Seeing that the 9th WR in that draft went 57th overall, Nico looks like a 2nd round pick. Not a 1st, but still good value seeing that the Texans spent a 3rd round pick.