While I know some of the folks here swear off checking luggage, I'm not one of those people :D I tend to check a bag for longer vacations, and actually find myself having to travel domestically often enough with at least one checked bag for work (usually a big Pelican case full of stuff I very much don't want to lose).
For the last year, I've been using Apple Airtags for my checked bags (and carry on, even). These are little disc-shaped, roughly quarter-sized devices that work with your "Find My" app on your iPhone (if you're an Apple/iPhone user). You can use em on things like your keychains to always know where house and car keys are, put them in a purse or backpack to know where that is, and put them in to your checked luggage so you can follow it as it approaches the baggage carousel, be sure it made it on your plane in the first place, be sure your luggage is where you left it on the train, etc. They use bluetooth, also, so don't interfere with plane systems or anything like that.
I've been able to follow my bags on my phone and essentially watch in real time as they're loaded on to my plane, or on the way to the baggage claim, or even when the large Pelican case has ended up at the oversized baggage claim area instead of the regular carousel.
I haven't seen a thread on here about them yet, so just in case anyone is wondering if there's a device out there that could work for keeping track of bags when you might have to separate yourself from them or worries out losing belongings too often, definitely look in to them! I can confirm they do indeed work quite well and can give you very precise readings on where your items are.