How many stages in history have been harder than Lanciano + Blockhaus in women's cycling? Given the small knowledge I have on this topic, the field tends to split on very easy climbs, so today should be absolute carnage given than Lanciano in itself is a monstrous climb and don't get me started on Blockhaus.
It's a lot harder to find profiles from the old Grand Boucle days and the Giro under Fanini and before, so hard to say what there was back in the days of Canins, Marsal and their likes, although through the Luperini days, Monte Serra was the main MTF, often climbed twice in the stage, so nothing that you'd say is comparable to Lanciano and Blockhaus. There were stages with Glandon or Croix-de-Fer preceding the traditional Vaujany MTF in the Grand Boucle but overall stage profiles are difficult to come by. There were some very hard stages in the 90s, but the field wasn't really deep enough to sustain it, and the organisers then overcompensated by almost wiping the proper mountain stage off the map and it's been a hard battle to get them back.
Since the turn of the millennium we've largely seen the major mountain stages be dominated by Unipuerto as a theory, which a number of people (Edita Pučinskaite, Nicole Cooke, Nicole Brändli, Annemiek van Vleuten and Cecilie Uttrup Ludwig to name a few) have criticised. The Giro went to a policy of having a 'classic' climb most years, often cribbed from men's cycling, with the Madonna del Ghisallo the most commonplace. Oftentimes there isn't really a pure mountain stage as tough as this, but there are some with cumulative climbing that totals up to a comparable amount - take the 2016 Alassio stage with Ginestro (9km @ 6%), Nava (11km @ 6,5%), Caprauna (8km @ 7,5%) and Madonna della Guardia MTF (10km @ 5,7%), or the San Lorenzo Dorsino stage in 2022 with Fai della Paganella (14km @ 6%), Durone (10km @ 6%) and Daone (7km @ 9%) before two uncategorised climbs at the end. The 2010 Giro had a hard back to back, with stage 8 from Chiavenna to Livigno including Malojapass (32km @ 4,7%) and then the easy side of Berninapass (18km @ 3,5%) and Forcola di Livgno (4km @ 7%) before stage 9 being a short stage of Livigno to Stelvio with Eira (6,5km @ 6%), Foscagno (4km @ 6,7%) and of course the Stelvio MTF from Bormio (21km @ 7,5%). However that was a super short stage and Stelvio isn't much harder than Blockhaus (though altitude is a factor of course) while Lanciano is clearly tougher than the preceding climbs there.
Now, at the same time, the Tour de France Féminin has a stage with Glandon and Alpe d'Huez ready for next month which surely is at a similar level - Blockhaus is harder than Alpe d'Huez but Glandon is harder than Lanciano - but definitely although a similar profile, this doublette is harder than Aspin-Tourmalet from the 2023 Tour. The Markstein stage in 2022 was otherwise the toughest, with Petit Ballon (9,5km @ 8%), Platzerwasel (7km @ 8,5%) and Grand Ballon (14km @ 6,5%). The Vuelta lags behind also; the same format of "two tough climbs, MTF at second one" that is becoming more popular for women's races appears to have been used for the Lagos de Covadonga stage in 2023, but they climbed the easier side of Mohandi that year as lead in, and likewise for this year's queen stage to Valdesquí, but with Morcuera and Cotos, and ain't nobody ever going to suggest that those are a harder doublette than Lanciano and Blockhaus.
Smaller races are much less likely to go all in on the climbing, with many simply happy to go Unipuerto as shorter race distances mean big mountains are more likely to imbalance the parcours. Occasionally the Tour de l'Ardêche may give us something (2020's stage to Font d'Urle with Limouches (11km @ 6,2%), La Bataille (8km @ 5,5%), Col de Carri via Col de La Machine (19km @ 5% with the first 8km @ 8%) and an MTF at Font d'Urle (7km @ 5,5%), for example, and they've also had the Col de la Mûre and MTFs at Mont-Serein and Mont Ventoux). Emakumeen Bira would frequently have a lot of up and down, but given the nature of climbs in the Basque Country, never would they be as long and involved as these ascents.
There is the possibility that some of the non-UCI races in Latin America are tougher, but even then I wouldn't count on it as the scene varies in strength, however there have been some pretty strong mountain stages in the Vuelta a Colombia Feminina; a lot however prefer circuit races with a Unipuerto or similar and on top of that, getting profiles from some of these races is hard. You can usually tell how difficult a race in that neck of the woods will have been by judging on how far Lilibeth Chacón wins it by.