Really only you can and should decide what you want to do.´, but there are points to consider.
Right now, I too think you should make a list of pros and cons.
On the con side: life in a block of flats can be noisy - we moved out of a flat when we got new neighbours who allowed their children to run, jump off chairs or sofas, and shout and scream at all hours of the day in the flat just above ours.
City live was becoming hard to put up with too on account of pollution, our bikes being stolen regularly, or not so bad, but still annoying moved from where we had put them, or had their tyres deflated.
Post was delivered to neighbours who did not bother to hand it in, and no amount of complaining to the postal service did any good.
Rates, local taxes etc. are likely to be higher in the city than in a country area.
Right now when considering a move you need to be very conscious of what kind of heating the flat has and what it costs.
Obvious pros are that you will probably be within easy reach of shops, doctor, etc.., able to go to concerts, the theatre, museums and the like if your budget allows and these things interest you.
Please do not assume that if you move nearer your children and grand-children you will automatically see more of them. Plenty of gransnetters have been disapointed in this respect.
If after listing pros and cons you still feel the need of advice, by all means contact your children, but do please make it clear whether you want their advice, or are simply informing them as to what you have made your mind up to do.
The reason they have not been in touch since you broached the matter could be that they did not realise that you wanted to discuss things- if they thought you were merely informing them of your intentions then they may not have felt they had anything useful to say.