@cdarwin for the most part this is bullshit
"everything after the "?" can be removed without issue" thats not true. try that with a youtube link, or a ddg search page
anything with `utm_` absolutely can be removed, they're google tracking params. `si=` is also a share id, yes
almost never, if ever, can these be used by website operators to figure out who you talk to, either
but for example `q` on search results page will contain the search query; `v` and `pp` on youtube are "video id" and "playlist id", respectively
on ecommerce sites, they can often be variant ids
firefox has a "copy without tracking" you can try but it doesnt work well in my experience