Thank you for your prompt response.
“We have a thousand performance threads in here, so I advice searching.” => Very true. I’ve already found Please Help! Extremely glitchy on MBP - #17 by jaslangdon and Sorry, a dumb 'Which CPU' Topic - #21 by LarsBjerregaard .
But, your summary is useful… Bottomline: I should buy a new desktop gaming PC, or, an Apple M 
My GPU: that Radeon is a “dedicated” GPU for laptops… Nice name, but very basic, benchmarks aren’t great.