A well explained answer is given in the reference below. Quoted as it is from the text.

Practical implementation of a transformer with relatively  large energy storage capability is always a challenge. The air gap is where the energy is stored, so a high-power flyback converter design needs a relatively large air gap. As a result of this, the magnetizing inductance is going to be quite small. The aforementioned challenge is actually achieving such as a small magnetizing inductance with low leakage inductance. A flyback converter built with a transformer that has large leakage flux and poor coupling will have poor energy transfer efficiency. Mainly for this reason, the flyback converters are generally not designed for high power. As a result, the flyback topology finds a limited role in photovoltaic applications only at very low power as a microinverter

Reference

Tamyurek, B.; Kirimer, B., "An Interleaved High-Power Flyback Inverter for Photovoltaic Applications," Power Electronics, IEEE Transactions on , vol.PP, no.99, pp.1,1
doi: 10.1109/TPEL.2014.2332503