I think that rule of thumb is wrong and it’s important to consider we live in Ritz Carlton of locations for homes. Do heaters and a/c have any easier life than in SD? Yards, home exteriors, roofs?
I’m pretty sue I’ve been well under 6k. My landscaper was $1200/year but fired him 8 years ago and put in drought tolerant for well under $10k that looks much nicer too. Spent $3500 to paint exterior 7 years ago and won’t need to do that again for a long time. New fences were 3k about six years ago and those will last 20+ years. No pool to care for, only HOA of about $1500/yr but that includes pool, gym, tennis, parks and more I use often. I’m sure many of my neighbors spend more by choice but that’s a different matter