Hi there. Two years is really quite old for a hamster
Yes they start slowing down - a bit like humans - and tend to nap or sleep more but can be quite happy with a slower lifestyle and can still be quite active out of the cage. Our last Syrian lived to 2 years 8 months and still used his wheel until about 2 weeks before he died (just for a minute or so!). And he was still very active on the level but not good with climbing any more.
So keep an eye on how he/she is managing. It can be an idea to lower everything to avoid risks of falls is his mobility seems a bit stiffer or less agile.