If you work for nice people and things just don't align, yeah, sure, this approach may be fine, but it's by no means universal.
The most risk-averse strategy should still use some of the advice posted here, but concerns like minimizing other people's problems and your own guilt are not worth the dangers.
That's correct – although I definitely take on board some of the other commenters' feedback about things like visas tied to roles. I'm going to add some clarification to make it clear this really relates to employees in good standing in tech companies (obviously a tiny minority of the populace and one of the few groups who have the guarantee you mention).
Any personal effects that I'm not using regularly have already snuck home with me during the previous week or two. Documentation I've been meaning to write has at least been attempted to be cleaned up.
And while that may be better in the long term, it's not so good if you want to keep earning while you find your next move.