The reality is a little less glamorous.
The salaries can be larger than average in some roles, but then again, as you will be working longer hours, your overall hourly wage will be somewhat less. Also, bonus? Interesting. You can work hard all year, deliver, be on track for a nice share of the pie, then bang! Some tard on the desk does a run of bad trades, or worse, hides losses, or the firm gets hit with regulatory fines, then bang - either a small bonus or more famously, a doughnut (zero bonus), with the promise that next year will be better. Just work as hard or harder, and maybe, just maybe, a bonus will come later. Maybe.
If you have ever worked in a competent professional IT setup, your eyes will bleed, your heart sink, your soul evaporate when you are exposed to the full horror of banking IT.
Sybase ASE - you will see schemas with 1000's of tables and many more stored procs - not because they are all needed, but because each one is a sticky plaster fix on the last sticky plaster fix. Oh, and almost nothing gets retired, it just grows like a slow cancer, consuming all that get near to it.
Offshore and nearshore vendor staff will "own" and manage and support the infrastructure, help desk, request system, application support and maybe even more. It will be hell on earth just to get access to one of your application log files to help troubleshoot why johnny-fucked-the-pooch trader tard tries to blame the application for his poor selection of trades.
You will watch so-called partners and peers travel with ease and get what they need, as they work 'for the business', on a business cost-code. You will be on an IT cost-code, and you will need director sign-off for a trip to the bathroom.
In short - the banks need IT, and they are basically fucked without it. But then treat it worse than the department that fills up the vending machine with coke cans each day. The reason is because YOUR management, IT management seem destined to fuck you harder than the business ever would. I never knew people could stand or walk without a spine, till I saw IT management.