Choosing Hi-Fi Systems

10-year old stuff should be fine (assuming good condition). The specs/performance of solid state electronics hasn't changed that much. The internal designs have changed, and the electronic components are getting cheaper all the time... But in general, the sound is not better. If you get truly vintage tube equipment, you are likely to get sub-standard performance (unless you get really top-notch gear).

With a more modern receiver (or amp, etc.) you are likely to get more power. Most cheap receivers now have around 100W per channel. Also, home theater receivers have digital inputs (for a DVD or Blu-Ray player) and surround sound.

Modern receivers (even one that's 10 years old) may not have a "phono" input. So, you'll need a phone preamp, or a turntable with a built-in preamp. Most new turntables that have USB also have line-level outputs, so you don't need a separate preamp if you get one of those. Direct drive turntables seem to "last forever", so if you buy a used direct-drive, hopefully it will not give you any trouble.

If you get a used turntable, it's probably a good idea to get a new cartridge (which will of-course, will come with a new stylus). Most new turntables don't come with a cartridge (except for the cheaper ones, which are often "ready to go".) Shure's best cartridge sells for under $100 USD, and I wouldn't spend more than that since no matter how much you spend, you are still playing analog vinyl.

Speakers are the most important thing for sound quality. Speaker design hasn't changed that much. The "style" has changed to smaller speakers (sometimes with a separate subwoofer) but a good 40-year old speaker can sound just as good as a modern speaker (assuming good condition).

I wouldn't hold-off on that. CD (or other digital sources) are better than analog and a cheap CD player usually sounds just as good as a high-end one. And, if you get a receiver (instead of a seperate preamp/power amp), it will have a tuner.