Hey bwb, sorry for my delayed response, I'm not even sure if it's relevant anymore but here are a few thoughts/items from my perspective.
I started my journey about 10 years ago with a simple MacBook Air and an external monitor at home. I used the MBA 'on the go' and when I was home I would plug it into the external monitor for dual screens. Once I realized how much more productive I could be that way I began slowly buying my into the multiple-computer, multiple-monitor ecosystem. Some people have 'normal' use cases and others have unique use cases so at the end of the day everyone's set up just has to work for them. After a while I began to realize that my computer was my most important 'tool'. Meaning, it is the single device that enables me to live my life. It's how I work, communicate, play, etc. more than just about anything else. I easily spend 8 hours per day in front of a computer and some days more like 12 hours. So I began spending more and more money on computer setups. I also eventually decided that things that were meant to work together were better for me. While I enjoy tinkering now and then, work became more important and I needed things that were designed to work together and that wouldn't be 'broken' by one manufacturer's update or require constant adjustments by me when an OS or firmware updated. I was in the Apple ecosystem so I went down the Apple rabbit hole and it has worked well for me. I do pay the 'Apple tax' but it's worth it for my use case.
I solely used a 13" MBP for a couple of years. It was my travel computer and my 'desktop'. When home I would plug it into what eventually became a multi-external-monitor setup. I got to the point where I believed an external GPU was worth it and bought into the BlackMagic eGPU as well - my 2016 MBP was driving the internal monitor, an external LG ultra wide (QHD) and an LG5K Ultrafine and the BMeGPU seemed to take the load off the internal GPU. People can talk technical details all day long but my individual experience is that the eGPU helped drive all those external pixels and reduced the strain on the MBP.
My 2016 MBP began to get a little long in the tooth (it's 4 yrs old now) and I also got to the point where I disliked removing it from my home setup every time I need to run somewhere so I began looking into a replacement. I already had keyboard, mouse and external monitors (plus eGPU) so the Mac mini made a lot of sense. I was exactly who Apple is targeting with the MacMini, I already had everything I just needed a computer refresh/upgrade without breaking the bank. Also, because I already had the MBP I cold just let that sit on a shelf and grab-and-go when needed. The MacMini ended up being a relatively cheap way to have a 'desktop' setup and 'travel' setup that worked for me. Once COVID hit and everything moved to video-calls I havent used my MBP much at all. It basically sits there 90% of the time.
Separately, I bought a iPad for...well fun. Kids use it, wife uses it, it's ok for occasional very short trips around town, but it just can't replicate the work I need done from a business perspective. I must use very traditional apps for my work - Microsoft Office suite, Adobe PDF suite, chat, mail, calendar, etc. - but not in a light consumer way. I'm probably more akin to an a power user of those and I routinely need multiple spreadsheets, PDFs, research tabs/browsers, and chat/email open at all times. On a bad day, I need 3-4 Word docs, a couple Excel files, a couple PDFs, a couple browser windows open at all times and must constantly cross reference everything for hours at a time. iOS just can't do that. I'm not talking about the simple clip here, swipe, paste there stuff. I'm talking perfectly matching accounting and document formatting along with nuanced, finalized wording for $$$ proposals or make-or-break customer interactions. iOS just can't cut it for me. I've gotten to the point where I won't even finalize anything on a laptop if I dont have to. I need my home setup to make sure i'm not missing something.
Long diatribe there but if you move toward the more professional (in the classic sense of the term, not the modern/everyone calls themselves a pro sense) use case and already have an external monitor plus peripherals the MacMini is a relatively cheap way to work in the Apple ecosystem from your 'battlestation'. From there it's just a question of how you want to work while traveling.
