I use final cut and logic all the time. I think I have actually come out ahead financially despite owning a Mac because
1) Adobe creative cloud subscription is expensive
2) Avid Pro Tools subscription is also expensive
Tell me how the math works out in favor of owning a PC.. I use a MacBook pro and paid just over $2k for it 4 years ago
The fact that you're actively using a four year old entry-level MBP, FCP, LP, and no reference monitor means one of two things:
1) You aren't actually the target market for this equipment, because you're not doing high-end HDR 4/8K video production work for broadcast or digital film mastering. This also means you don't NEED tools like Adobe or Avid, or Apple's "XDR" monitor. I've already illustrated the financial cost penalty with this system under that usage scenario with the rhetorical CIO post.
2) You are the target market for this equipment, because you yourself aren't technically savvy enough to understand what you actually need and how Apple's hardware prices and platform lock-in are financially bleeding you through their walled garden. Given even MBPs are overpriced for what you get, non-upgradable, non-user-repairable, and have non-trivial QC issues, and you're asking this question... it means you don't actually know what options you actually have.
Let's talk hypothetical, here. You could have easily gotten a high-end Windows-based notebook or portable workstation from Dell's Latitude or Precision line with a comparable configuration to your MBP new for about 2/3rds the cost at the time, or a refurb/open box from Dell directly of a slightly older model that still would have tagged the performance of your 2015 MBP for around half the cost.
If you were new to video editing or open to learning something new given you're only using FCP, you could have easily gone for Sony Vegas, DaVinci, Lightworks, or OpenShot on the video end, and either FL Studio, Reaper, Cubase or Tracktion on the audio end - all of which are multi-platform editors. Assuming you paid $1500 for the laptop and $500 for FCP/LP with that $2000 price quote, even paying $600 for Vegas and $200 for FL Studio Producer or Reaper (the more expensive of those options without really exceeding the features you have) coupled with a fully new $1000 laptop, you're still 10% cheaper ($200 less) going Windows, and gotten more capable software in the process. If you went with a $800 refurb/open box special and could get away with the free version of DaVinci/riding the beta of Lightworks/using OpenShot on the video end and using even the $100 end of any of the audio editors, that's still roughly $1100 cheaper. More than half. Even if you'd gone with the MBP and the cross-platform software, you'd still have spent an extra $500 just for the laptop to run OSX over Windows. And you could still upgrade/replace hard drives, RAM, replace batteries at a reasonable price without taking it to a Genius Bar, spend more for higher end software/upgrades that could do more than Apple's titles going with the Dells...
I'm glad your setup is working for you, and you're happy with what you got out of it for the money... but the fact that you did choose that path, and it fits your needs means you're more of an under-educated prosumer (or as I less kindly stated, Youtube hobbyist, no genuine offense intended). Real professionals who live and die by Adobe's software workflow (those who can justify the cost), or are needing ridiculous processing power moved on years ago when Apple stopped putting out anything remotely resembling real pro-grade equipment. The fact that you haven't, and your work can't justify the cost of the 800lb. gorilla software suites associated with it... well... Apple exploited your gaps in knowledge and cashed in on their loudly touted history with creative types to the tune, of, about a grand in opportunity cost in your case and locked you into a software workflow that's proprietary and beholden to their hardware.
Personally, if I'd been in your shoes with a $2000 budget in 2015 and needing to do low-end HD video editing and music work but wanted to use the absolute best tools for the money in a laptop form factor, I'd have recommended a Dell Latitude E6440, DaVinci Resolve and Cubase Artist... though honestly at the time, if it had been for myself, I'd have probably gone Ubuntu Studio with some workflow involving Cinelerra, Blender, Synfig, LMMS and Audacity depending on what I was doing... mostly because I was already familiar with the stuff to varying degrees... or if I'd been using Windows at the time, gone with the free version of DaVinci or OpenShot with Blender and Synfig, and probably entry level FL Studio and Audacity on a used Thinkpad W520 for around $750. Of course, I'm not you, and YMMV. However, you wanted to know.
There you go, a good half dozen options yielding as good or better results for varying degrees of not insignificant levels of less money with greater flexibility for the level of work being performed and the hardware needed to do it.