[polemic]

The simplicity of interstellar travel really depends on how you define it.

Constructing a ship of sufficient redundancy / self-repair capability that can carry embryonic life to another star seems like something we could achieve. The engineering problems seem hard but quantifiable, and the resources required are likely available. If humanity decided tomorrow that we needed to put "a human" on another planet, I think it could be done (sent) within a lifetime. (surviving there, another matter)

OTOH the scale of resources that would need to be deployed to begin construction of a Dyson sphere would seem to be immense, let alone the systems required to harness it for anything useful.

[exe34]

you put a bunch of solar panels and furnaces on mercury, and use that to dismantle it and rail-gun the pieces into space.