Is they no middle ground option?
I’d probably say ~16-28 weeks (4-7 months) on a geared drivetrain with reasonable maintenance and cleaning, dependant on the bike and amount / type of use its seeing – maybe a shade more/less…
SS bike I use 1/8″ KMC chains for about a year with minimal maintenance and then bin em along with the sprocket/chainring…
Surely it depends more on the bike and its use.
I guess 6 weeks if you were constantly hammering it through muddy shitty weather every day for 5+ hours or so with little or no maintenance, then I could see it being required, but chains are a bit more durable than that generally…