Largely because the bulk were/are being built as luxury cars. Musk offered his entry level cars (3 and Y) with tons of tech. Electric seats, cameras all round, AI, driver aids, touch screen etc etc. The ICE manufacturers recognising the competition went to create their own but as Tesla were so successful they needed to offer a similar level of bells and whistles - but given that Tesla were selling well at around £50k, they didn't need to be cheaper than that.Dunno why EVs are so much.
We are now starting to get some proper entry level EVs where the difference in price between ICE and EV is small. The Dacia Spring EV is £15k and is the EV alternative to the Sandero which is 13k.