Hiring companies might prefer to just have this as a "hoop." There are, inevitably, some people who apply to a lot of jobs. Jobs they aren't qualified for. Low intent applications, where the applicant isn't really that interested. Etc. Even if these are a minority, they apply to a lot of jobs. In any case, standardizing job applications (OP seems to be talking about application forms that are mostly resume-ish fields…
They should ask for a cover letter. I agree that a hoop is needed - I recently posted a job on LinkedIn which has some kind of "click to apply" functionality, and it was clear that most of the applicants were just lazy clickers that probably hadn't even read the posting. On the other hand, if you make people jump through pointless procedural hoops, you're screening for people who are ok doing that. Ask for a cover le…
A cover letter is a kind of writing contest, or maybe it's perceived that way by a candidate. Writing about yourself can be stressful.
I'm not saying not to, ask for a cover letter. Just saying that this stuff is nuanced. Standardisation is great when you want very low friction. Job applications aren't frictionless, probably can't/shouldn't be. Some copy paste fields might be inelegant, but it's not changing the friction equation by much.