$10 may not feel like much, but it's the proportional costs that you have to figure out.

If that's e.g. for a monthly $1000 investment, it means 1% of your savings is lost in fees each time. That'll be 1% that's not going into savings. If you end up with a million by some time, that small fee will have cost you 1% of that, which is $10k.

"It's just a cup of coffee" -> "that's a 10 000$ cup of coffee". But if you only save 200 a month, that 5% is 200k you've lost by the end.

One percent is often considered a reasonable cost ratio, but it's definitely worth considering what the real numbers are for a given option.