> You couldn't consume gigabytes because that amount of ram didn't exist.

No, they didn't consume gigabytes because they were written is such a way that they didn't need to. Run one of those programs on a modern computer with gigabytes of ram and it still won't. It was as easy then as ever to write software that demanded more resources than available; the scarcity at the time was just the reason programmers cared enough to fix their bugs.

> You still had apps with the same issues that would eat all your ram.

The worst offenders back then had objectively smaller issues than what would be considered good now.

> Computers crashed all the fucking time for dumb bugs. I remember being shocked when I upgraded to XP and could go a full day without a BSOD.

Because XP could handle more faults, not because the programs running on XP were better written.