You can still send a payment from HSBC, for free, instantly, to any other UK bank account. You can also just about do most things in their online banking. This more than can be said for some other parts of Europe.
My wife is with HSBC and the iOS app doubles as both a banking interface, and the authorisation code response generator.
When she's in a web browser and needs to generate a code for the HSBC website (eg to add a new payee), she has to log out of the phone app to be able to get to the response code UI.
It blows my mind every time she does it. How on earth did they come up with that UX. It's like they're actively trying to be awful.
Apologies to anyone reading this who worked on this at HSBC, but yikes!
I suspect the flow you noticed actually helps enforce that - if they gave you a code to let you use on the website, they'd have to log you out of the app anyway.
However, over the past few years they've really improved. The website is now consistent across all tabs (at least that I use for personal banking) and the app is simplified with most functionality needed for personal use in there.
On the personal side, I've always found the people at branches of HSBC (regardless of where you go) to be courteous and professional relative to the few others banks I have accounts with. I'm not in the UK, so perhaps things are different there, but in North America I've found them to be a slight step above average (insofar as you can be for retail banking --- it's all relative!).
nationwide and natwest have much better apps and websites
I still ditched them for Monzo though, mostly because natwest's anti-fraud system was reliably triggered by my mostly-online transactions, 3-4 times a year.