PS+ games locked

I'm starting to question how useful and worthy downloading big games from PS+ really is. I paid for a year sub and a few big games like RDR2 and Horizon among others are no longer available on PS+ therefore they show the padlock on the PS5 and are unplayable, yet they are still taking the full HDD space (102GB for Horizon!).
RDR2 was only available for like 6 months, from like April to Nov last year, this feels more like a demo than anything...

What's your thoughts on this? Is it a scam?