I think the goal should be to keep expanding your audience instead of letting it taper off or solely making content to maintain your subs count. To do just that will provide a steady income for a period of time but it's also a stupid business model.
If STPeach is a brand that also cares about her fans on some level, phoning in post-shower selfies or workout videos in skimpy clothing for a steady revenue stream that likely will dwindle over time is suggestive of someone who has a bad sense of what it takes to maintain profitability/bankability. Onlyfans, Fansly and Twitch obviously are how she makes money and her name is worth something - therefore, she needs to treat her partnerships with these platforms like a business and brand pairing by using good business judgment and savvy. Whatever market you're in is going to have its own best practices for staying profitable/bankable, but certain things are consistent with most markets and staying competitive includes finding new ways to bring in subs for sustained performance and success on an individual creator level.
A naive Onlyfans creator starting out that only uploads bikini selfies will maybe wonder how she'll be able to make more money because her subs count might be lower than she likes and therefore her earnings aren't quite kosher. She knows Onlyfans is known for porn-level content but she's not comfortable either having sex or masturbating on camera for the world to see. Fair enough. She decides to see what other non-nude creators are doing and takes notes on what they do. Her poses get sexier and more suggestive, maybe she's OK with showing a little skin like sideboob or the side of her ass. Her sub count gets better, but she's not raking in as much as she'd like.
Example continued: Statistically, there are 1.5 million Onlyfans content creators active. She's nowhere in the top 1,000. The ones in the top 1,000 are able to pull in money for a number of different reasons - their name is a brand/recognizable/they're a celebrity, their content is good/diverse, they're attractive, etc. Our example creator is cute enough to be noticed but not worth the coin that other more popular creators are getting because they're mostly doing things she either hasn't considered or has had her own misgivings towards doing. Her reasons might be personal - Onlyfans isn't her primary source of income, she's afraid of what it might mean for her reputation outside of the Internet, she has personal or religious standards she doesn't want to violate. At some point, she'll have to confront these dilemmas and decide if pushing her own personal envelope is worth the prospect of making more money - and the good/bad that comes with it. She might not end up in the top 1000 unless she somehow taps into a weird niche or genre that she can live with acting out for money, but her best chances of getting noticed are ensured when she joins the nudity club at the very least.
Even if Lisa/Peach ranks in the top 1,000 Onlyfans creators, her net worth doesn't come close to that of Amouranth or Meg Turney. Much as we have laughed about Lisa whooping it up with Amouranth and other content creators, this is a promotional strategy on some level to help boost her subs count. This is one way of boosting the numbers but it's not a wave she'll be able to ride forever. The strength of her content is going to probably guarantee her longest-term success in this game and we've collectively soured on what she's up to lately. Her name and brand aren't strong enough on their own to carry her for many years on Onlyfans if she's planning on being around for a while.