I am on a grandfathered Tuta plan that costs me about $2 CAD a month. I also pay for Proton's premium plan. Both are worth it to me. I get that everybody has a budget but at the same time 10 Euros a year is a tight one when dealing with privacy friendly alternatives.
PublicLewdness
I use the TOTP option in KeePassXC and KeePassDX to handle 2FA duties. I backup the encrypted file to my Nextcloud. If you self host Nextcloud or something similar this is a viable option.
I have gotten tech minded friends to switch with some success. Getting my wife to switch to privacy friendly communications with me was easy in that I did all of the leg work. I setup her accounts and installed the apps. As far as she was concerned the phone came with XMPP, Matrix and Tuta.
Reading this for the first time now. Going to need a new camera app......
I have switched my comunications to anything else. XMPP, Matrix, Session, Jami, etc. I text as little as I can. No matter the app the messages still go to my carrier.
I have tried both Jerboa and lemmur. I don't mind either but both have given me issues logging in from tiem to time.
I have used DivestOS on my Pixel 2 for a while now so I donated. Glad to see the fundraising was successful.
If we're talking about mobile apps only then ntfy, Fluffy Chat, KDE Connect, Nextcloud, Tuta, Protonmail, Session, Conversations, Organic Maps, Fedilab, Mull, DAVx and KeePassDX.