For complex projects moving to esbuild from say Webpack is not necessarily easy.
Why would things be easy in a complex project? If you've built complexity into your project it seems a little unreasonable to expect someone else's tool to fix that for you. At some point you need to accept that building things that are simple is your own responsibility. But building things that are simple is incredibly hard so don't be too down on yourself if your project is complex. Software complexity is like entropy; it's very easy to add complexity to a system, and very hard to remove it.
It's also worth noting that you probably don't really want a tool to make your complex project appear more simple. That would only hide the complexity from you, but it would still be there. If your project is complex then your best approach to solving that is a lot of documentation, a lot of testing, and a lot of refactoring.
Why would things be easy in a complex project? If you've built complexity into your project it seems a little unreasonable to expect someone else's tool to fix that for you. At some point you need to accept that building things that are simple is your own responsibility. But building things that are simple is incredibly hard so don't be too down on yourself if your project is complex. Software complexity is like entropy; it's very easy to add complexity to a system, and very hard to remove it.
It's also worth noting that you probably don't really want a tool to make your complex project appear more simple. That would only hide the complexity from you, but it would still be there. If your project is complex then your best approach to solving that is a lot of documentation, a lot of testing, and a lot of refactoring.