Is your feature request related to a problem? Please describe.
Currently, ~~foo~~ in wikitext renders to HTML <strike>foo</strike>

Describe the solution you'd like
Change it to <s>

Describe alternatives you've considered
None

Additional context
Other inline markup (from the first table here) is rendered to the same HTML by wikitext and Markdown. Only differences I could tell briefly are: Markdown renders s for strikethrough, and doesn't support highlight and underline. Regardless of semantics or specs, this should be changed for consistency, to bring the output of both types closer (better for testing, styling, and consuming TW output).

Wikitext already favours other semantic tags (strong instead of b, em instead of i) since 10+ years (?)

Browser support for both elements is the same (everyone has supported both for as long as anyone knows):
https://caniuse.com/mdn-html_elements_s
https://caniuse.com/mdn-html_elements_strike

strike is obsoleted in HTML5 the HTML Living Standard. Both were deprecated in HTML 4.0 and we kept using them, so this is the least important reason.