Are we seriously going to sit here and pretend that Lautaro couldn't in any way, shape or form be replaced by someone else? Not even by the two attackers we are most closely linked to in, oh, I dunno, Dybala and Lukaku? I'm not a fan of the former, but the latter is almost guaranteed to give you at least 15 goals in Serie A, and if Marotta doesn't think Dybala has the qualities to replace someone like Lautaro, why is he hell-bent on giving him one of the biggest contracts in the squad?
Not saying there is much truth to the rumos, but 90 million euros would be a daylight robbery for Lautaro "I was very close to joining Barcelona" Martinez.
Skriniar, on the other hand, bleeds black and blue, and most importantly, plays the outer right centerback in our defense. That position is no joke, whilst most defenders are capable of playing in the middle. There's no way of knowing if Bremer (say we buy him) even has the capabiltiies or phyisical characteristics to play in that position. We know D'Ambrosio can deputize, but that is about it.
So what does selling Skriniar amount to? At this minute, if nothing else happens, Bastoni - De Vrij - D'Ambro. Alright, with the way especially De Vrij has been playing, that's a Lazio-worthy defense at best. So you're forced to find alternatives - the logical one would be Bremer, but his price is rising steadily (40 million, probably). As much as I love D'Ambro, he's not good enough to start 38 games. So, you're likely looking at Milenkovic for 15 million, and there's nothing that I've seen from him, that tells me he isn't a major downgrade to Skriniar.
Alright, you've uprooted two-thirds of your defence, sold Skriniar, likely the future captain and locker-room leader who has publicly stated he wants to stay forvever and clearly cherishes playing here for (maybe) 70 million and bought replacements for 55 million euros (that's if you can even buy Bremer). You've earned 15 million, and to get to that 60 million deficit, you need to sell another starter.
"Easier to replace" my ass.