My current partner and I have what we both deem a great romantic relationship and friendship. We plan to get married for legal benefits and stay together for some time. We could care less what it says about our relationship, but there are simply legal things that make sense. It's likely we will never divorce. But we both can envision worlds where divorce happens. If it happens after 30 years of great partnership, so be it. It doesn't invalidate those great years we had. But if it does happen, we would want a fair and just split after it. Not based on 50/50, and not necessarily based on "yours is yours, mine is mine". Neither of us would want to leave the other in financial trouble, but if one of us made much more than the other, we both agree that it would be fairer to give that person some sort of better split, so long as it does not dramatically hurt the others remaining life. It'd also depend on the life goals of each of us from that point and who would need the money more for their respective goals. What we find fair may be different than others, but given the scope of the agreement it's really only about what we both see as fair.
We trust each other 100%. We could probably act on this type of agreement without a lawyer. But no one ever knows how divorce will go down, so why not put it in writing?
All of this isn't to say that there can't be nefarious reasons at work here and is not to invalidate or ignore the terrible way tech treats women. But this is not a categorical thing, and it really comes down to the specific agreement and the two people involved, presuming neither side is coerced or uninformed about the agreement.