Only if you satisfy a long list of conditions. The reason this is the case is that Switzerland sorts kids very early, at 12 years essentially. Get sorted wrongly
once and while you do get a second chance, they make sure it takes you 2 years absolute minimum, 4-6 years normally and even more is possible to enter university. Oh, and if you get sorted wrong (lang or kurzgymnasium), it takes years
and expensive courses to get back.
The low tuition only applies if you enter before you turn 25 years old. And Zurich is very expensive to rent a room.
Even once in university, you only get one chance (you should see the crying on results day), if you want to redo a year, you can do it in Germany (closest) or France/Italy that do allow it. Which of course is anything but cheap, as a non-local you do not qualify for any kind of aid.
But sure, what you say is correct, tuition is not that high and if you really try, yes you can get through it as a very poor person. But one mistake and it'll take you a very long time to claw back, and a lot of money.
(this is about ETH Zurich, EPFL is similar, but not quite as bad)