British aristocracy without WWI

I have heard it said on this website that WWI greatly diminished the power of the British aristocracy as their heirs died in battle and many went bankrupt funding the war. How true is this? If it is true, what would British aristocracy and the political landscape look like in the absence of WWI or in the absence of British participation in the war? What would this mean for government and everyday life in Britain? Would the House of Lords be more powerful? What effects, if any, would it have of the Empire/Commonwealth?
No WWI = No or at least delayed and reduced death duties. This alone will delay the decline in importance of the aristocracy. Equally important is that their servants will not have gotten used to factory work and the increased wages they earned doing it.
Far better . I'm certain we lost Prime Ministers in the trenches. I also find the thought of taxing the estate of someone who died for his country distasteful.