Maybe we should make a similar spreadsheet which tells you the time required to be top 10/100/1000... At each event, I could obviously do it quite easily with the current results but there is probably a way of making it update automatically.
I've tried something similar before but failed. You just need to embed the respective elements to your site but I can't seem to extract them from WCA's result page.
RE: OP's question, I'd say anything above +1 SD (top 30ish%) makes you certifiably 'good', in the general sense. But if you're asking if any individual is any good, then it's always going to be 'well, what's good for you?'. The answer to that will depend on complicated things like hours invested * intensity of effort; factors like propensity for future improvement, availability of free time/attention for thinking about cubing, perhaps whether they're surrounded by other cubers all day - or have learned and developed completely solo. There's also a thing where the spectrum for who gets to be classed as 'good' depends a lot on who you ask (i.e. how competitive they are).
In a way I appreciate how a few have simply put ridiculously fast times, because there's some truth to it. Either you're pursuing self-mastery, relative excellence, where 'good' is totally dependent on where you're at in your development, how much work you know you've put into getting better - which is to say there's no single answer to your question. Or, you're pursuing absolute excellence, that's to say you're looking to be among the very best in your chosen pursuit - in which case the definitive answer is always and only 'better than #1'.