Inoreader worked okay for me, syncs with the client apps I use, and was fairly Feedly-like. But I eventually went to a self-hosted FreshRSS install due to the ads that got inserted into feeds.

If you’re concerned about things like FOSS, you should consider finding a way to self-host, either on hardware you own or using a cloud VPS. Any service that can sync and keep client compatibility updated is going to incur costs, and they’ll extract that value from you somehow - ads, data slurping, whatever. Better to pay for it yourself so you at least have a clear idea what the relationship is.

1. Hack together a proof of concept
2. Works well enough that management slaps a “done” sticker on it
3. Pile of hacks becomes load bearing
4. One or two dependencies change, the whole thing falls over
5. Set evenings and weekends on fire to fix it
6. Management brags about moving fast and breaking things, engineers quit and become cabbage farmers and woodworkers
7. New graduates are hired, GOTO 1

It’s a consequence of the terminally-online brain rot idea that if you do not explicitly state that you are against a bad thing, you must be actually a huge supporter of it. Or that if you do explicitly state that you are against a bad thing, the fact that you didn’t mention a different bad thing means you are a huge supporter of it. Ad nauseam.

A single AA battery is going to discharge itself just sitting on the shelf over a decade

Any free weather data is either being subsided by the cost of the device or harvesting your location data for ad surveillance purposes. Paying for carrot means the developer gets to put food on the table without telling ad networks wherever you are.