I have bought a couple of rebuilt titles. They're actually becoming more popular as vehicles are getting more and more pricey.
Is it too risky? Well yes and no. Depends on your threshold of risk. I bought a 2015 corvette with a flood title. Almost everyone thought I was insane but I did my homework and the price was right. The person who rebuilt it (new carpet, new computer, rebuilt the engine etc put about 15k miles on it over 4 years after the rebuild. I also inspected it before the purchase. I figured at worse I had roughly $12k to put into it if something is wrong before it would have been worth buying without rebuilt title.
There's a company in Fort Worth that rebuilds trucks and they have a great reputation. They use oem parts and make sure everything is aligned and within spec before selling. They also charge more but it's still way cheaper than retail.
I would A. Check the carfax and then google the vin. Most of the time google will have a cache of auction pictures you can look at. You can see the damage before it was rebuilt. One truck I was looking at had a description of "small fender bender that insurance didn't want to cover". After I googled the vin the entire front in was caved in. I obviously passed.
Make sure your insurance will insure it. Geico had no issue with mine. I also paid cash so I didn't have to worry about financing it but some banks won't finance.
Get a PPI done if you don't want to inspect it yourself. Have them look at welds, alignment etc. then take it on a 30 minute test drive. Make the engine heat all the way up.
Lastly is resale value. This scares most people off from rebuilt titles but it's like anything else you want to sell in life. If you price it right it will sell. Yes it is well below retail but it was also well below retail when you bought it.