If Havertz sees out the season in his current form, we should place faith in him, and in Jesus continuing, though I'm less certain about that, as our central forward options.
Havertz's runs and raum-deutering have been superb of late, we don't need him to take on dead balls, and his first half, full pace, first touch versus Brentford before sliding that chip over Flekken to the right was quality. His work rate and all round game are good.
He is entering his prime and if he has personality issues, they're the polar opposite of someone like Toney's. If we sign a marquee name as a competitor and presumed starter, we would have to expect an unpleasant decline in Havertz's morale and form as a consequence. Keeping this relatively egoless guy around who's willing to play left back at time of need seems like a good deal if he's gonna be non-shit.