I'm typing right now on the same system though I only have the 500 GB SSD instead of the 1 TB. It's a great system that I bought in 2018 for $1,100. I also recently bought a MacBook Air 16/1TB and played with it for about 30 minutes. The Air/M1 is a much better machine but we paid around $1,800 for it so lots more $$$ for the 16 GB and 1 TB SSD.
If I needed a new machine right now, I'd get the Air/M1. The battery life alone would make it very useful to me but the stellar performance is an absolute bonus. Touch ID and the weight are further factors.
The 2015 will give you the ports - if you have a lot of stuff, and, right now, my 2015 is hooked up to a 4k display, a QHD display, keyboard, mouse, speakers, Ethernet and sometimes my Time Machine disk. You get the nice SD slot if you need additional storage that's removable. That said, it is a six-year-old machine. My 2008 MacBook Pro 17 served me for ten years before too many things died on it. I'm still using a Late 2009 iMac 27. But you're always living on borrowed time after about five years.
I bought the 2015 MacBook Pro 15 as a backup for my 2014 MacBook Pro 15. I can't afford to be down and my 2014 was getting old so I bought a used 2015 for backup. If either dies, I can just get any data off Time Machine for either system and use the one that works and then get a hold of another backup or primary system. If you earn your living from your computer, you should have a backup.
Apple's going to release a bunch of M1X systems this year and next year and there is a tremendous amount of progress in the second generation systems. So that further complicates the decision.
The 2015 I bought had dings and dents in it. It has scratches on the bottom cover. I really don't care how it looks - it just gets the job done and that's all I care about. Laptops are meant to be used and cosmetic issues never bother me.
The 2015 is a workhorse; I think that mine will last a full ten years though I'm pretty sure that I will either sell it or it will be a backup when I get an M1X MacBook Pro or Air.