Considering Congress passes almost 500 laws per year (1229 from 2019 to 2021, 1234 [sic] from 2021 to 2023), it is a little less than 1% of cases.
But that’s just the federal branch. Your list includes states and local municipalities - which makes the real number much, much lower. Much closer, arguably, to 0.1% or less of all legislation.
> Much closer, arguably, to 0.1% or less of all legislation.
You're missing the giant flip side of that coin; that local, state, and Federal courts can all determine laws conflict with other laws or the Constitution, and do so regularly.
If your town passes a "no black people allowed after 10pm" law, it'll never get to SCOTUS, but it's still unconstitutional. The first level of courts it encounters will immediately overturn it.
(Two other notes: clearly unconstitutional laws tend to be a bit rare, because they're a bit embarassing when they get readily overturned. A significant portion - as much as 20% - of those 500 average bills is naming post offices; for example, https://www.congress.gov/bill/117th-congress/house-bill/203. Much of the rest are similarly void of thorny constitutional questions.)
The fact remains that it is entirely within the role of the court to overturn unconstitutional legislation, which the court does regularly.
The idea that the court would not give proper scrutiny to a legislative act -- one which may violate the first amendment, fifth amendment, and may amount to an illegal bill of attainder -- just because it had support from the senate, well, that's just preposterous.
But that’s just the federal branch. Your list includes states and local municipalities - which makes the real number much, much lower. Much closer, arguably, to 0.1% or less of all legislation.