Unfortunately, it's simply too late in the game for them to start developing high performance ICE powertrains. In the time it would take to iterate and perfect everything over a couple generations (fifteen years or so) in order to build up a legitimate performance name for themselves, everything they worked so hard on would be on the verge of obsolescence.
Fitzgerald's comments back in 2017 (which C&D mentions) basically reflect his opinion on the situation:
"Performance will not be on the same forefront of differentiator as it is today for ICEs [internal combustion engines]. Everybody is capable of doing an electric motor and putting it in a car, so the performance values will almost be the same. Nobody’s going to be interested in ‘A’ or ‘B’, so I think that will come down to a level playing field."
"If you look at the performance value of an electric vehicle today, there are a lot of ICEs that really struggle to keep up with that."
https://www.motoring.com.au/no-n-per...enesis-109048/
It is clear the Fitzgerald is biding time until the Genesis brand starts building electric vehicles before turning up the performance. We will see eventually if his thoughts and approach are validated.
In the meantime, they've got that crusty old Tau V8 from yester-year in the G80 and G90, easily bested by today's turbocharged six cylinder engines, and it's a shame if they don't do something to rectify that situation. If they are done with V8 development, that's fine - a modern development of their Lambda V6, such as turbocharging the 3.8L version up to 450hp+ would be better than just letting everything languish until they start building competitive PHEVs or EVs (who knows when that'll be feasible).
Not chasing the existing ultra high performance players is a reasonable approach when you are just trying get a foothold with the brand. Being woefully behind the competition's performance and powertrain technology with your flagship sedans is less understandable.