For what it's worth, a couple of years ago I lived through the position you are in right now. Our situations may not be exactly the same but if they are close, here are my thoughts:
All things being equal, buy the setup you want. Budget always impacts what we buy but if you can afford something a little more expensive I say go for it. I've spent too much money on some useless things in my life but I can't think of a time when I said "I shouldn't have bought that much memory, storage, portability, connectivity, screen, etc". In fact, most of the time, I've felt like I could have bought more computer performance than I settled on. Especially with Apple devices, they last a long time.
Timing matters. What you needed yesterday isn't what you will need tomorrow. Try to look forward as much as possible and buy what you will need for the next couple of years. Currently, I think that means portability. Most of us are a whole lot more remote than we used to be. If that is your situation, then prioritize portability.
I started with a 13" MBP and slowly grew into multiple external monitors. Over time I added eGPU, a dock, external hard drives and every couple of years I upgraded the MBP. Eventually I had a full blown workstation at home that I plugged-in to and unplugged the MBP from. After a while I got tired of the small annoyances that plugging/unplugging caused and instead of upgrading my MBP I bought a MacMini. So then I had a MacMini desktop setup like I was back in the 1990s (monitors, dock, lights, speakers, keyboard, etc) as well as an older MBP for portability. Then last year my MBP was getting a little too old and I replaced it with a middle-end 13" M1 MBA. Based on your response above I believe you are in a similar situation as I am in that we're one of the people for whom a iPad does not work. When I'm mobile, I need computer not a tablet.
So now I have a MacMini with all the peripherals like a traditional desktop setup and a M1 MBA for portability. Everything automatically syncs via iCloud, Adobe Connect, Microsoft One Drive, and Google Drive and it works pretty good 99% of the time. Every now and then, when I haven't looked at my MBA in a month, I have to open it up and let it update/sync before I grab it and go. This is hard to explain but the small but constant annoyances that happen when you unplug/replug a laptop from your desk setup every day (windows shifting all over the place, software glitches, occasional kernel panics, monitors not being recognized, bluetooth devices not connecting, drives not remounting, etc.) are about the same as the less frequent but slightly more problematic issues when you grab your separate laptop and go (a file or app isn't sync'd).
So what do I recommend? I'd say get the laptop and slowly build out a home setup (years) that you can unplug and replug from. Once you get tired of the issues that come with it, look into what's available and buy what you need then.