First of all, the list includes players that contradict the idea of a cheap slam. Kontaveit, right now, would be favored against more than half of those listed in a h2h on hard court and grass. Furthermore, winning on grass is generally about holding your games and Kontaveit has one of the highest hold % over the past year. Hell, simply holding a huge number of serves in WTA is a recipe for winning a lot.Active players who've made at least a SF at Wimbledon:
Barty, Sabalenka, Pliskova, Muguruza, Svitolina, Kvitova, Kerber, Halep, Ostapenko, Azarenka, Bouchard
Technically still active:
Serena, Venus, Clijsters
Active players who've won Eastbourne:
That's hardly a small list considering the closest thing you've got to a dud is Bouchard and most of those are the biggest champions of this era. Wimbledon isn't RG where every year is a lottery, it's the opposite in fact, it's the one slam where the cream rise to the top even when the field is pitiful and the closest thing you get to an exception is someone like Bartoli who reached multiple Wimbledon finals.
If she's going to luck into a slam it'll be on a hardcourt where Jennifer Brady can make a slam final out of no where and then disappear as fast as she rose. Wimbledon isn't a cheap slam to win and the fact it's prestige has survived the last decade has only added to it's lustre.