DS (DC2) was coming up on 4 when he was out of daytime nappies, over 4 when he was (consistently) dry at night. DD (DC1) was in pants at 2.9 in less a week (wasn't going to attempt it till she was 3 but gave it a go out of curiosity and got a surprise).
So much pressure to toilet train when in actual fact it's an individualised complex process that involves recognising a physical sensation and linking it with a predicted outcome.
Yes, I'm sure nappies feel better than they used to be but that won't make much of a difference for long, it's not about that for children. If it is, it means they were ready anyway.
Before washing machines, people used to want their children out of cloth nappies early when they were having to handwash them (don't blame them) and therefore any poo in the toilet was a bonus but it means we now have a skewed notion of how early that should be.
Save yourselves the drama and don't even attempt it till they're 3. And if it doesn't work, stop quickly and try again a few months later. Life's too short and we all get there in the end.
Plus you want them to be consistently dry - repeated accidents (wee or poo) mean they are not ready and it's stressful for everyone. Remember, UCAS don't award additional points for how young you were the last time you wore a nappy...