The larger the pilot group, the more secure a pilot will feel about a choice to stay at said pilot group. Talk to most guys who decide to stay and listening to their reasoning and that is a big reason they feel its a safe choice. The larger a carrier, the more stability you will see. It will take a lot of guys to be furloughed for them to feel a hit in QOL of life or even become worried about being furloughed themselves. This also motivates them less when taking the time to apply to a legacy even if they aren't a lifer.

Obviously, this is based on anecdotal evidence as there is no way to prove this without a complete survey of all pilots at every carrier. You can't even count on those results as pilots would likely lie to prevent deterring pilots from going to their carrier.
Which carrier are you at? I'm guessing not RAH or it would be pretty obvious after talking to most CAs on the YX or S5 certs. I have talked to many guys that just upgraded at RAH that have already decided they are not going anywhere else even with more than 20 years left.

Right now, certain carriers are seeing higher attrition from the top (like Endeavor or AWAC) due to the uncertainty and less chance of feeling safe. Guys who once considered their carriers a career stop are feeling the pressure to move on. I know RAH is seeing ~20 pilots a month leaving from the CA list. I have heard of rates around 30-50 at other airlines. What is the attrition rate at your carrier?

When a legacy hires a class of 50, they don't hire more guys from the larger carriers. Usually, you will see a couple of guys from each carrier and background (unless a flow exists). So when TSA or Commutair have one guy leave that is a much higher percentage of their pilot group even if two or three of the guys are from RAH. They don't hire 20 guys from RAH and 1 guy from TSA because its a bigger airline. They try to diversify their new hire classes.