Best alternative to Photoshop?

Best alternative to Photoshop?

I'm not willing to pay a subscription to Adobe when I only use an image editor occasionally.

Definitely need a 'user friendly' interface, good selection tools, feathering and airbrush painting. Also need online tutorials... (YouTube?) 

I have identified these but not sure which is best or if there is a better alternative....

PIXELMATOR Classic £28.99 www.pixelmator.com/tutorials

AFFINITY PHOTO £23.99 (YouTube online tutorials??)

LUMINAR price ? (YouTube online tutorials??)

( I have Photoshop 6 on my old MacBook but it won't work on my new MacBook Pro running Big Sur OS. And I aim to sell the old MacBook )

I'll pay up to about £35.

Thanks

?2021-02-19T17:58:39Z

I've used Paint Shop Pro for years and now it's owned by Corel. Very nice and the features have grown over the years. I've also used Photoshop but to me PSP is easier to just do some quick tasks. Cost I can't say right now, Google it. I believe you can get a trial, too. I know it's under $100.