Apparently the PS3 received a system performance update in early 2020 (version 4.86), and now the user interface runs like new again. Hooked up to my 4K TV, and it almost feels
How To Install/Update To 4.86 HEN/HFW On Any PS3 + Enable HEN, MultiMan, Webman! [EPISODE 11] - YouTube
PlayStation 3: disponibile il nuovo aggiornamento 4.86 per la storica console - Justnerd.it
PlayStation 3: Sony releases Firmware 4.86 for their 13 year old console - HFW 4.86 released, SEN Enabler updated & PS3HEN to be updated soon due to no kernel changes! - Wololo.net