Pulling from actual discussions (names anonymized):
The Rockstar logo didn't appear. Instead, a dialogue box popped up. It wasn't the usual Windows prompt; it looked like something drawn in MS Paint. The font was Comic Sans.
Leo stared at the two options. There was no 'No'. There was no exit.
If you ever want to play GTA Online — even just to mess around with friends — the Isoromscom version is useless. It’s hard-coded to skip online checks. To play online legitimately, you’d have to buy the full game and re-download 100+ GB. Your save files? Not compatible without manual editing.