I would say it is certainly worth it as it contributed towards your stores ecosystem
Shopify autogenerates the site maps check out this post https://help.shopify.com/en/manual/promoting-marketing/seo/find-site-map#find-your-sitemap-file
You can then submit this sitemap into your Google Search console
Let me know if you need any help with this!
On most Shopify sites I've seen, Google crawls most pages every day or two without doing anything. Why do you need to recrawl the whole site faster than this?
This is an accepted solution.
Yeah I mean once it's in the index, they tend to be crawled with good frequency. However I've noticed some (new) stores taking a month or more to become indexed. Worth setting up GSC and making sure it has the correct sitemap URL as good practice. But it's not a magic bullet, and there's no guarantee doing that will get you indexed, or get you indexed faster, but it ups the chances a bit.