I thought carry-on weight restrictions have been in force for a good while now..? If not, I dread to think of the weight of some stuff that people would take into the cabin with them.
Although in theory, the 23 kg is great with BA, it does seem a bit excessive! How on earth does someone lift that weight into the overhead lockers?! Besides that, if it falls for whatever reason, that's some serious damage to someone should it hit them.
Latest information on weight restrictions on the link below:
https://www.skyscanner.net/news/cabi...t-restrictions