I switched to a simple HSBC current account about 4 years ago. In hindsight this was probably one of the worst decisions I’ve ever made.

It’s been error after error due to antiquated systems, poorly trained staff and broken promises resulting in hours and hours of wasted time. I rarely contact HSBC. When I have it's been a dire experience originating from a simple request. I have a good half dozen eye-watering examples but this is probably the worst:

Request: Please close my savings account and transfer monies into my current account.

Service Provided: Tried to close my current account and transfer monies into my savings account.

Outcome: 4am activity on my phone with plethora of notifications of cancelled DDs, etc. Panic as I thought I’d been hacked. I demanded an investigation and charged them £150p/h + VAT for the time it took me to reinstate DDs, daily phone calls to checks if scheduled DDs were happening (HSBC unable to confirm), buy a new policy that elapsed if DD was ever cancelled. 4 weeks of hell. Battered them for a 4-figure compensation and got it. Very rare for me to go medieval / jumanji / apoplectic but I'm afraid I did.

Can anyone recommend a decent, customer service orientated, simple to use, 21st century technology driven current account please? I’m not really into package accounts. All I want is decent service.

You may find this an unacceptable reply as First Direct is part of HSBC and yet I have banked with them for over 20 years and never had a single problem. My banking is very active if not complex.
Initially I used a telephone service, now I rarely telephone and do practically everything online and yet if I need to the telephone staff respond promptly and helpfully.
It would appear that others agree, they have consistently good reviews.

Not v trendy but I like nationwide. Been with them since 16. I do everthing online. Have phoned them maybe 2-3 times in 10 years. However nationwide is Changing now it has a CEO is keen to expand and ramp up his bonuses. Not like the old building society mutual culture it was

I use Handelsbanken whom I cannot recommend too highly. You have a personal account manager for whom nothing is too much trouble. All is handled at branch level. No commissions so staff never try and sell you crap. No use of call centres or algorithms.

I had previously banked with First Direct but sacked them when we had a row over some ridiculous fee they wanted to charge me. 6 years later I got a refund and apology from them. By then I had completely forgotten about it.

Yes, I pay Handelsbanken £25/month for current account and high limit charge card. That comes with a high overdraft at 8% if I ever want to use it. To my mind that is easily worth it for the personal relationship and to avoid OP's issues. It's about what you would pay for an Amex card. With free banking you get what you pay for and all is fine until it isn't.