It has always been difficult to put DD down for naps.
I think it was around 15 months where DD could skip her nap and show little to no ill-effects.
Ever since she turned 2, that trick where you skip the nap so you can get them to go to sleep earlier has stopped working.
Nevertheless, we still strive to get DD one good nap in the day. She must wake up from her nap before 3 or we will really be in for it at bedtime. And, the only way I can get her to sleep is by putting her in my ergo with her fave blankie and dancing around to her favorite song while I do my chores. It takes anywhere from 15-45 minutes. She won't even sleep in the car anymore.
We just really think it is important for her to get a bit of a recharge in the middle of the day. I do notice subtle little things when she has not napped.
So, we are still napping at 26 months. She gets one. They are 45 minutes long. (I lay her down in her bed.)
ETA some advice: I was always surprised how early DD seemed able to nap. From 12-18 months she would get up at 8 and take her nap at 11. Also, I think having them on a sleep/nap schedule that is down to the minute is really key. They need to get up at the same time, take a nap at the same time, and go to sleep at the same time every day. There is a lot to be said about your body clock. It really works. Now, with DD it is still hard, but if we stray from her schedule it get really hard.
And, DD never slept in a crib, so I am confused why a transition to a toddler bed makes any difference. Is it because they don't stay in bed? Because, DD would never stay in bed and just go to sleep for a nap. never. We just have to get creative.