CRM selection heavily depends on stage of the company and GTM motion complexity. I would never recommend to anyone to ever start with SFDC, but I can't not recommend ending there.
csv file with emails + python thing to send them using postmark
it took an hour every time I had to do anything, and I ended up with a collection of python scripts that solved random problems that were already solved somewhere else, which grew and grew
I tried a few programmable shared inbox tools and they were all clunky and meh. tried lighter things like supabase + some golang list manager, also meh.
postmark has a CRM they acquired, iirc it was too expensive
zoho seems reasonable on price, but did not try it
but to be clear, even if I paid up for something dumb like hubspot, my life would have been simpler and better