Sony A7 ii photos not sharp as expected (compared to, for example, Sony A3000)

[XKAES]

Since I have no idea what "well-defined", "decent", "sharpness", "bad", "best", etc. mean to you, so it's difficult to respond in any meaningful way -- other than to say, a prime lens will normally outperform a zoom lens under any condition.  Zoom lenses were created for convenience, not optimum results.