A brief history of efforts that went beyond the usual copying of ideas:
Around 2004 Sauber paid Ferrari for the CAD models of their previous years car. They tested models from the CAD in the wind tunnel and then on the track and found that they were a second a lap lower than expected. I won't go into the why, other than saying it some time for Sauber to make much progress.
The next big attempt to use another teams aero concept was by Haas, where they paid to use the Ferrari wind tunnel to develop their car and bought as much as they could from Ferrari. They also paid to have Ferrari aero staff join their team. Ultimately this resulted in a rules changes from the FIA, with 3 months minimum gardening leave when transferring between Ferrari and Haas and back again (relationship benefited both). This was why Haas were able to come in with a small team and seem to do a very good job in the first couple of years.
Haas have continued to use as much of the Ferrari car as they can (and their wind tunnel, just like Racing Point now use the Merc wind tunnel), but at 50% the size of Racing Point they do not have the resource to do a good enough job to get closer to Ferrari, and clearly this year the Ferrari is not a championship challenger.
Renault are a factory backed team, so they could not really copy RBR in the way that Racing Point has copied Merc, as they would have to then admit that their technical department was not up to the job and then they might as well give up. So they changed their technical leadership as that was the obvious step after McLaren beat them last year.
Around 2004 Sauber paid Ferrari for the CAD models of their previous years car. They tested models from the CAD in the wind tunnel and then on the track and found that they were a second a lap lower than expected. I won't go into the why, other than saying it some time for Sauber to make much progress.
The next big attempt to use another teams aero concept was by Haas, where they paid to use the Ferrari wind tunnel to develop their car and bought as much as they could from Ferrari. They also paid to have Ferrari aero staff join their team. Ultimately this resulted in a rules changes from the FIA, with 3 months minimum gardening leave when transferring between Ferrari and Haas and back again (relationship benefited both). This was why Haas were able to come in with a small team and seem to do a very good job in the first couple of years.
Haas have continued to use as much of the Ferrari car as they can (and their wind tunnel, just like Racing Point now use the Merc wind tunnel), but at 50% the size of Racing Point they do not have the resource to do a good enough job to get closer to Ferrari, and clearly this year the Ferrari is not a championship challenger.
Renault are a factory backed team, so they could not really copy RBR in the way that Racing Point has copied Merc, as they would have to then admit that their technical department was not up to the job and then they might as well give up. So they changed their technical leadership as that was the obvious step after McLaren beat them last year.