Any good reasons to use transistor phono stage and line level preamp instead of tube ?

Sound quality is different. Not better, just different.
From a practicality standpoint, transistors trump tubes every day. Lower power, longer life, lower noise (usually) vs. tubes.

Is a particular transistor phono pre better or worse to your ears than another tube phono pre ? That's a judgement call between you, your ears and your wallet.

Best,
E