My sister is the worst. She has low-tier status in one FFP. That drives her decisions a lot. I mean, there is a price that she finds prohibitive and where she chooses another carrier. Usually, though, she just books direct with her preferred carrier, sometimes switching the travel dates a bit if that saves money and she is flexible.
The thing is she keeps asking me for advice but never follows it. (We aren't kids; we both have been flying and working for some time.
Many of us on FT have higher level status and can tend to forget that even lower-level status within an FF program can be enough to take flying from "miserable" to "bearable/tolerable." At least for US domestic FF programs, even the lowest levels (DL Silver, AA Gold, UA Silver, AS MVP, etc.) offer decent benefits, from checked baggage allowance to preferred seat selection, priority at check-in, security, and boarding, upgrades to Comfort Plus, Economy Plus, Main Cabin Extra, Premium, etc. and sometimes discounts on advance purchases for C+/MCE/E+/Premium, a (supposedly) faster phone line (which can be useful in IROPS), and depending on your travel patterns, even occasional upgrades to F. Another big benefit is IROPS rebooking priority. One of my favorite cases as justification to myself for maintaining even low level status in a slower travel year is, even as a lowly DL Silver Medallion several years ago, I misconnected and was placed on standby for an alternate flight. 55+ people waiting on Standby for 3 seats on that flight. I was #2 on the list, cleared, and made it home for Christmas. 50+ had to find another way to get to where they were trying to go.
Conversely, every time I island hop in Hawaii on HA and have to do so without status, even if things run somewhat smoothly, I'm reminded of why even low-level status can make a world of difference, so in many ways, I can't fault your sister.