So I’m of the opinion that unless you go to school for engineering, specialties like healthcare, financial - college is quickly reaching the point of not worth the cost investment. I say that to say I get where you are coming from.

So if not doing a 529 you have a few options.

1. Real Estate Investment which is passive income for you and them. The money/equity would appreciate and you’d be generating passive income that they could either take over and/or you could take out equity in 25 years or so.
2. Stocks. I get not wanting to lose the money and you won’t really lose savings but cds at best “might” keep up with inflation. Historically if you stuck money in an index fund S&P as an example, you’d never lose money on any 20 year period. You’d typically would gain quite a bit. So you wouldn’t have ot baby sit it but just ike your 401k you’d have to realize you’d have some very good years (last 10 before 2022) and some not great years ike this year. But over the lifetime of it you’d appreciate quite a bit.