It really is individual. You’ve not mentioned if you’re living together or have any plans for the future re mortgages, marriage, kids etc.?
I found it was really difficult being a very low earner in a casual living apart relationship with a higher earner, nice guy but he had no concept of the stress I was under trying to stay afloat. One day I mentioned I was exhausted and he asked why I didn’t quit one of my jobs or drop some hours. He didn’t get that I wasn’t working my fingers to the bone for savings or a cushion, it was purely to scrape by.
When I met DH I was earning alright and he was a student, by the time we were TTC we were both earning about equal, but in the not so distant future he’ll be out earning me by at least 50%, possibly doubling my wage. It’s not an issue as I’m still earning well, though if I was on min wage and he was on a great salary I suspect over time it would lead to issues as my lower salary would be curtailing our options and financial stability. We share all money but it would feel strange imo if one of us was on a high wage while the other was on the bare minimum. Not because we’re not a team or anything, it would just feel like a big disparity for two people building a life for one to be contributing so much less financially.
But of course it depends on your circumstances. If the lower earner takes on the bulk of childcare then they’re working at that despite it being unpaid. Running a house is work. No matter what, if you plan on children make sure you’re married first and that you always have access to the household money. I was and am happy to go part time after having a child because I was at the top of my career while DH was only getting started (age difference) but I would never have agreed to stop working full time had we not been married.
Only you know whether it’s an issue, you should always feel able to talk about money openly and make sure you’re on the same page. If I were the higher earner I would insist on DH having the same amount of spending money and money in savings as me, and I expect and have the same the other way around. Once you’re married there should be no ‘mine and yours’, it’s all ‘ours’, but problems can arise if there’s the perception that the lower earner isn’t working as hard or isn’t as ambitious or is just coasting having a nice lifestyle because of the higher earner’s efforts, I’ve seen that a lot.
There’s also what you’re doing for work to take into account, if you’ve chosen a profession and it’s not super well paid but you’re working hard at it that’s different imo to being content working in retail for example for your whole life (chosen as an example as that’s something I did for a decade), some would be perfectly fine with that but some value ambition and drive and I value those qualities in a partner. I guess that’s the crux of it: if one partner is highly ambitious and driven then it can cause problems if they feel the other isn’t, but that’s on them not to choose a partner who isn’t those things.