REC709 or sRGB Monitor

If my editing timeline is REC709 and my intended audience is online (YouTube for example), will YouTube recognize that the video is REC709 and convert the gamma to display properly on a typical home computer that uses sRGB?

If someone uses their smart TV to access YouTube, will it match REC709 more accurately than a computer monitor? Or if I plug a USB into a TV, do you expect it to display an MP4 as REC709?

During editing, is it better to use a monitor that is capable of a REC709 profile, or just use an sRGB monitor so that I see the same thing an end user with a PC will see?

What video editing software are you using?

Have you considered using Davinci Resolve color management (also affects gamma)?

I don't think YouTube messes with the gamma, except maybe when making a tone-mapped Rec.709 version from an HDR source, but I think their main goal is to compress the life out of your clip.

Rec.709 & sRGB are very similar, so most viewers likely wouldn't notice the difference, but I would recommend that you buy or rent a colorimeter and make an sRGb calibration profile for when you're editing photos, and a Rec.709 profile for when you're editing videos. There's no need to switch from an sRGB monitor to a Rec.709 TV, just calibrate your monitor with DisplayCal.

The best you can do is give them a video edited with a calibrated monitor, but once it hits YouTube, all bets are off, as phones, tables, PC monitors, & TVs have a huge variance in black levels, brightness ratings, contrast ratios, tints, etc. I remember at one point, only Chrome would display YouTube videos correctly, but I'm sure they fixed that issue long ago.