The purpose of rebarreling your current or old rifle is simple, it saves money and gets you a top notch rifle. If you order a new custom from any smith it's going to be $2,000+ and a new Remington 5R is $1000 and comes with a crappy trigger. So you have to drop another $150-200 on a trigger. So you're $1200 into a factory rifle that's either going to be a good one or a bad one. Or you pay $800 for the new barrel and the smith to true your action and install the barrel, buy a $200-300 stock, and a $150-200 trigger. Heck he could even skip the $200-300 charge to true the action and just have a new barrel installed. I have a couple Remingtons that weren't 100% trued up and just rebarreled with Bartlein barrels and they shoot 3/8" groups consistently.
At the max he's in it $1300 but will have a semi custom rifle with the same quality stock that comes on the Remington 5R and a good 2-3lb trigger from Timney or TriggerTech. I guarantee it will be less picky, easier to clean, and shoot better and be more consistent than the factory barrel too. There's no point in having an old rifle sit around taking up space when you can build off of it and make it better. The old gun is useless to me if it doesn't shoot good or isn't some kind of heirloom or masterpiece.