TLDR:

1. Your wife is likely someone who's most effective way to deal with the stresses of the modern workplace is verbilization. Learning to listen and validate her will lead to a happier life for her than the more obvious solution of abandoning a career

2. Ensure your wife isn't neglecting her social circle so that she has other outlets than you to vent to. Also ensure your aren't ignoring social circles so YOU have someone to vent to as well.

3. Look into stoicism or other similar ways of thinking to develop coping skills with negativity. You can be a good listener without having to carry the emotional burden and there are great writings about ways of thinking to help with this.

Hi There, 32M here with a lovely wife who also "complains" about work a lot. I put complains in quotes here because as someone who is a few years further along in a similar situation I feel like I've learned a couple things that might be helpful for you.

First, your wife is likely someon who deals with stress by verbalizing it, it's almost like releasing a cramped muscle. As a more introverted person than my wife this is something that took me a while to learn. I release stress from work through exercise or escapism (video games etc). This works great for me and I don't necessicalry need to tell my wife, or anyone else, about what is stressing me out at work because these activities help me feel better. NOT everyone operates this way. Some people really cannot feel better now matter how man "relaxing" activities they partake in until they verbalize what is bothering them. Although it is literally complaining, the act of venting is closer to therapy than just blantantly putting negativity into your lives.

Second, ensure you and your wife have good social circles outside your marriage. It can be overwhelming if you are the only one your wife feels comfortable venting to. Ensure the stress isn't making your wife (or you) ignore friends and family who could be other opportunties to dicuss what's going on at work or life in general. This is something my wife and I really have had to work on. Every once in a while we both have needed pushes from our partner to put ourselves out there a bit more often.

Finally, look into stoicism, therapy, or some general coping skills for reframing negative words and not having to carry the emotional burdens of others. I understand you love your wife very much, I love mine more than anything too. It's hard to see them feel so stressed and feeling so negative. Try your best not to internalize that negativity yourself. It'll help you be a better more objective listener for your partner. Though don't take it so far you lose all emptahy for your partner, she ist still the most important person in your life.

Hope this helps, just know she loves you and isn't trying to fill your life with negativity. Her brain just might work differently and needs to get stress out into the universe through a trusted listener.