The problem is that state-level actors don't just have a lot of money; they (and their decision makers) also put a much much lower value on their money than you do.
I would never think to spend a million dollars on securing my home network (including other non-dollar costs like inconveniencing myself). Let's suppose that spending $1M would force the US NSA to spend $10M to hack into my home network. The people making that decision aren't spending $10M of their own money; they're spending $10M of the government's money. The NSA doesn't care about $10M in the same way that I care about $1M.
As a result, securing yourself even against a dedicated attacker like Israel's NSO Group could cost way, way more than a simple budget analysis would imply. I'd have to make the costs of hacking me so high that someone at NSO would say "wait a minute, even we can't afford that!"
So, sure, "good enough" security is possible in principle, I think it's fair to say "You probably can't afford good-enough security against state-level actors."
I don't think so. State level actors also have limited ressources (and small states have very limited ressources) and everytime they deploy their tools, they risk that they get discovered and anyalized and added to the antivirus heuristics and with that rendered allmost worthless. Or they risk the attention of the intelligence agencies of your state. So when that happens, heads might be rolling, so the heads want to avoid that.
So if there is a state level group looking for easy targets for industry espionage - and they find a tough security, where it looks like people care - I would say chances are that they go look for more easy targets (of which there are plenty).
Unless of course there is a secret they absolutely want to have. Then yes, they will likely get in after a while, if the state backing it, is big enough.
But most hacking is done on easy targets, so "good enough" security means not beeing an easy target, which also means not getting hacked in most of the cases. That is the whole point of "good enough".