Been using a degoogled LineageOS phone with all apps being exclusively FLOSS. My favourite free alternatives to proprietary apps and services must be Lemmy (Jerboa) for Reddit, ArcaneChat and Matrix (Extera) for Telegram, Fluxer for Discord.
Which ones are your favourite?
Unfortunately a lot of people these days tend to conflate “private” or “not google” with “FOSS.” It’s one of the reasons I’m very adamant about not watering down the definition of FOSS, free software, or open source.