Google 'mason jar lighting trend'...

is this for a man cave?

Nope. A dining room. It's a copy of a relative's from a foreign country. Not sure if the other one has Mason jars but it is live edge, and Mason jars are kinda her vibe.

One offs like that are usually most appreciated by those who order it and that's how it should be. I would be honored if asked to do it.

Same. There's not really any way to make money woodworking unless you're Amish or have a huge shop, or if you manage to run a good YouTube channel. So I won't do any except for friends. But I do enjoy it, so I do it any chance I get

Is this a chanderlier? How will it be hung to keep it level? What's the purpose of the "remote control box"? Why not just control the lights with a wall dimmer? I'd rather have lights like these than mason jars.

It's hard to see but there's eye bolts that can be tightened or loosened to level it, it's mounted to a piece of flat bar that will span the rafters. I would probably do a short length of chain if the ceiling height will allow, as that will give me more options than interlinked eye bolts. It's an older house, not sure how accessable the switch is. A control box for a fan is pretty cheap, but it might not be necessary. Mason jars are kinda her vibe, the fixtures are pretty expensive unless I make them myself, which I think I can.

I love live edge walnut but not mason jars and for sure not Edison bulbs . I think this is great gift to a friend and you seem to have thought it out but a wall switch has to be somewhere for you to install the light even with a remote control for a fan there still neds to be electrical to the fan.unless of course abttery option that is a real PITA How do plan to get the holes through the mason jars ? Waht fixtures are you planning to "make yourself"

There is a switch to it now, but it might be in a corner that's not super easy to get to. The remote that I was thinking of was something like this
https://a.co/d/d6NrbOd
And the fixture would be like this
https://a.co/d/978MdMH
I'd drill a hole in the lid of the jar to fit this, install the lightbulb, and then put the jar on the lid.
Maybe they are going out of style, this area isn't exactly on the cutting edge of style, what is coming in right now?

That's a shelf over the dining table. That's not a design element that works for most spaces. Too heavy in appearance.

I would sooner select an 'artsy' wood branch and have this inexpensive LED rope light hanging from it to create a unique one-of-a-kind piece.

https://www.amazon.com/dp/B0B1DCYPJB/ref=twister_B0CJFKMLJ3?_encoding=UTF8&th=1

Here are some other photos for inspiration that aren't so heavy as live edge wood and mason jars

I'd consider a receiver and "fake" wall switch like this: DEWENWILS Wireless Light Switch and Receiver Kit

If the bulbs are to be within the jars, be sure to buy bulbs for enclosed fixtures, e.g. Euri Lighting Dimmable 5.5W 2700K 90 CRI Decorative Filament LED Bulb, Enclosed Fixture and Wet Rated, JA8 Compliant (Pack of 4)