Google's John Mueller said on Twitter that "that would be pretty rare" if you removed your tag and/or search pages from Google's index and preventing Google from crawling them, that it would it would result in a ranking boost for your site. He said you can try it and do what you want but it probably wouldn't result in a positive outcome in Google search.
John did add that "Probably those (tag/search) pages aren't primarily what you want to rank for." That implies removing them probably won't hurt your conversions or your web site goals. But it is up to you he said "though ultimately it's up to you to decide how & with which content you want your site represented in search."
Here are those tweets:
I think that would be pretty rare, though ultimately it's up to you to decide how & with which content you want your site represented in search. Probably those (tag/search) pages aren't primarily what you want to rank for.
— 🍌 John 🍌 (@JohnMu) January 8, 2020
Honestly, I believe a lot of SEOs do aim to remove tag or search result pages from being crawled and/or indexed by Google. This is generally an SEO strategy you would see in many SEO audits I believe?
Forum discussion at Twitter.