As Gunner says, every path is different. In my 2017's case, he did no college camps, played on a Connie Mack team that got zero exposure, and attended very few recruiting events, which included the NorCal World Series, HF, and Stanford during his rising senior year. That was more than enough. In fact, if he had attended only the first event, he would have ended up at the same D3, or he had attended only HF, he would have had many good options. Stanford was fine, but only one school of interest there recruited him, though the coach of his D3 was at Stanford unofficially, so it may have helped a bit.
I don't think my kid sent more than a few emails, but those were during Junior year and didn't generate much more than camp invites. IMO emails help make sure targeted coaches take a look at the kid at the showcase, but that's it. I did put together a highlight video for him, and I believe that sending that helped solidify interest among the coaches who reached out to him after the showcases.
As for camps, IMO they are fine to learn about a program and to get experience but they are not essential nor are they a reliable path to being recruited.
So my opinion is yes, HF and Showball are enough, assuming your kid has the skills required and shows up to play.
Of course grades are a very big deal if you're fishing in the high academic D3 pool, but I'm sure you know that.
And for your Covid question.... nobody knows what things will look like in summer of 2022. Hopefully they'll be more or less back to normal but who the heck knows.
Edit to add -- do a search of the site for the Arizona Fall Classic and the HA game there. Many folks here swear by both the Jr and Sr version of the event and there are some good threads.