If my papers are always accepted, should I submit future papers to journals more diffficult to get published in?
&quot;Then you are aiming too low&quot; - this may or may not be true. That you are not asked for major changes doesn't necessarily mean that your papers would have been accepted, maybe after major changes, in higher rated journals. The &quot;secret&quot; to get into higher rated journals is not to write papers that don't require much revision. It's rather about originality, having done the right thing at the right time, potential more general interest, impact, and influence, and difficulty. These things don't play a role for a reviewer who thinks about whether to accept with minor or major revisions. So whether your papers would be fit for higher rated journals cannot be said based on what is in your question.
That said, chances are (obviously depending on your career aims) that papers in top journals would improve your standing, CV, chances for grant success, so surely it makes sense to try to get into better journals if you have work that you feel is up for that (and maybe even with the best you have without that feeling, because maybe you're underestimating yourself). But read some stuff in top journals related to your work and try to learn about how these authors managed to get there (maybe you find out that this stuff doesn't look very different from yours, in which case go for it!).