Szczepan Bialek wrote:

A dipole with one ene earthed becomes a monopole.

Yes, and the characteristics of monopoles is different than the
characteristics of dipoles.

Hertz transmitter is a dipole.

A Hertz transmitter is a transmitter, not an antenna.

A Hertz antenna is a dipole.

The Tesla's is a monopole.

The Tesla's what?

Todays dipoles are simply the two monopoles.

The characteristics of monopoles is different than the characteristics of
dipoles.

Thanks this the waves are polarized.

Polarization has nothing to do with whether an antenna is a monopole or a
dipole.

But the question is if Marconi was right:"

He wasn't right, he was wrong.

"The necessity or utility of the earth connection has been sometimes
questioned, but in my opinion no practical system of wireless telegraphy
exists
where the instruments are not connected to earth."

Marconi was wrong.

Best regards,

Shut up, you babbling, little idiot.