On the other hand, providing capital increases the value of the labour applied. Giving a tradesperson and additional capital might mean they can afford better tools that allow them to work more quickly, accomplish more per hour of labour and therefore be able to charge more for that hour while the customer simultaneously pays less for the task being done. The tradesperson is then able to pay back that capital plus some gains for the person providing the capital. Everybody wins, the investor gets more money than they started with, the tradesperson earns more after paying back the investment than if they hadn’t taken it in the first place, and the customer gets a lower rate for the tasks that need to be performed.
The problem is when we let that scale up to the point of there being people with essentially endless funds to spend on things like mega-yachts and ridiculous mansions, while others aren’t even getting their basic needs met. The answer to me isn’t removing the benefits of capital income at all, but adding some progressive taxation to keep the net income more modest, and maybe some stronger/target employment regulation so the capital holders aren’t getting rich off labour that’s supported by government social programs.