@RolfBly I use TheOldReader for about ...150 feeds. phys.org is probably the businest and the biggest single source likely blogspot (20-odd blogs hosted there that I subscribe to feeds from).

thespinoff.co.nz is one of the few media outlets with decent feeds and IIRC they have a separate "paid subscriber" one (I pay, I set it up ages ago, it works so I haven't looked at it)