Apple is extremely user hostile and their lobbying efforts are especially disturbing. Their devices can be nice if you want something that's hardware-standardized and you don't care about price-value ratio or ethics or their lobbying or closedness. But you are relying on them being successful in setting the device up exactly how you need it. In OP's case, standardized hardware failed to guarantee good performance and now he's stuck with a high-priced device with poor upgradeablity.

Also, the Lightroom subjective experience as a measurement is a bit problematic, because Adobe products are the kind that prioritize featurefulness (aka bling) over performance and stability. I know it's a popular product suite: feel free to express opposite impressions. Adobe's answer to this (and it's not really fair to single Adobe out) is that you just need a beefier machine; that way the performance issues are offloaded to the user. I suspect that they constantly buy the fastest machines for their developers, because that way developers don't notice performance problems, so no time is spent on fixing performance.

I wish these developer companies would have a limit on how recent their dev hardware can be (or how powerful). That would cause them to address performance and save users a lot of money on upgrades. There would be other desirable secondary effects because addressing performance might lead to addressing technical debt (Adobe Photoshop has color management bugs dating back decades).