Everyone has the same problem. For example, Apple recently blocked a service that notifies you of parliamentary documents (source in Dutch: https://chaos.social/@[email protected]/117370967171338864)

Email receivers (be it Gmail or your local council) don't differentiate if you're self hosting or a business. So long as small businesses can manage (who have like one part-time sysadmin that also manages a ton of other IT stuff; email doesn't take much of their time), so can you. If you set up the usual suspects like SPF and DMARC, the domain is not a known spammer, and the IP not in a blocked address range, it's mostly hands-off (source: I self host my email)

If you need it to really be super reliable, yeah, you need to send through one of the big companies who have not just a dedicated sending IP address but entire ranges dedicated to email sending, as well as staff that will respond to delivery issues 24/7. Microsoft rejecting email from Google and vice versa isn't unheard of, so there aren't guarantees anywhere, but that would be your best bet. For my personal use, that extra nine of reliability isn't needed