The tank inspection is not a quick visual inspection. It’s take it out, empty it, fill and pressurize with water in a protective enclosure, measure the expansion strain, drain, dry, stamp the inspection date, reinstall, purge, and refill.
broader point still stands I think - if this was required of everyone every year, a secondary market like propane tanks for backyard grills, etc would probably emerge or it would be part of mfg warranties.
side note: no, I don't think market solves everything.
