I totally get you. When I was beginning with investing I first considered PostFinance. It’s feels super easy to have a bank account and trading all in one.
But then I calculated, that if I want to reach FIRE, I will probably need to purchase shares for 1’000’000 CHF and then probably sell a similar amount over the course of the rest of my life. PostFinance fees are like 0.3% of the transaction value + stamp duty 0.15% thats 0.45%. Since you pay it when you buy and sell, that makes it’s 0.9%. And that’s not including compounding!
Over the course of a lifetime, I guess sticking with PostFinance instead of IB could cost about a month longer of your work to reach FIRE in order to close that fees gap. Is it worth it? I don’t know, I’m starting to think that maybe it is, at least for some people.
By the way: have we reached consensus of how the US withholding tax for a broker like PostFinance works if you hold VTI? Are you worse off than IB or not? Edit: I also forgot that if you want to buy VTI with PF, you need to convert CHF to USD. Another cost.