"You never help around here" and "I've been feeling overwhelmed and could use more help" can point at the exact same problem. Only one of them is likely to start a fight. The difference isn't the issue itself, it's whether the sentence is built around your partner's failure or around your own experience.
"You" statements put your partner on defense before you finish the sentence
"You always" and "you never" are rarely accurate, and your partner usually knows it, which means part of their attention goes toward defending against the exaggeration instead of hearing the actual concern. The real issue gets buried under an argument about whether "always" is fair.
Name the feeling, not just the complaint
"The dishes are still in the sink" is an observation. "I feel unsupported when I'm handling this alone" names what's actually going on underneath it. The second version gives your partner something to respond to that isn't just an accusation, since a feeling is harder to argue with than a complaint.
"I" statements aren't a script, they're a starting point
Rigidly saying "I feel that you..." followed by a criticism is just blame with different grammar. The point isn't the exact phrasing, it's genuinely locating the sentence in your own experience: what you feel, what you need, rather than what your partner did wrong.
Timing changes how the same words land
The identical sentence said calmly, ten minutes after the frustrating moment, lands very differently than the same sentence snapped in the heat of it. If you notice you're too activated to say something without an edge, it's usually worth waiting a few minutes rather than getting the wording perfect while still upset.
The goal is to be understood, not to win the point
It's easy to slip into building a case, listing every related grievance to prove you're right. That approach might win an argument, but it rarely gets you what you actually wanted, which is usually for your partner to understand how you feel and respond to it.
Expressing a feeling clearly isn't about softening the truth. It's about aiming the sentence at what's actually going on for you, instead of aiming it at your partner.