We have been working on Crooked Stick this month and I was surprised to notice they don't have o.b. stakes anywhere, even though there are homes around part of the course. I don't know if it's club policy that you can play from somebody's back yard if that's where your ball is . . . it was the club itself that developed the homes, so there could be a covenant like that in the deeds . . . but I did like the lack of clutter, and the stakes would have been overkill for what must be a fairly rare occurrence.
For OB - If there is a clearly definable physical boundary line then there is no need for loads of additional white stakes, simply and clearly define the boundary in writing on the Local Rules.
This works at Private Members Clubs as they get used to the definition, and for external run events there are likely roving Rules Officials to adjudicate any marginal calls.
Back (years ago) when I ran PGA Events we would try and avoid painting miles and miles of white lines (& other colours) by using sensible definitions, otherwise the course ends up like a crime scene (and for long after we have moved on)!
Less (clutter) is more (beauty)
In the example -Red Stakes as a Penalty Area seems the most appropriate from the description.
OB White Stakes add a "Stroke & Distance" Penalty which is harsher, and play might be possible now the area has been cleared out?
If the area is determined to be a "No Play Area" (Penalty or otherwise; for player safety, or ecology/wildlife preservation etc.) then relief MUST be taken under Rule 17-1e.