@WatieKatie
Yes, sadly I have found this to be my experience too (and I've been on and off the apps for 5 years or so, so lots of dating experience!). I have dated men in their 30s to 40s normally but have found similarities with your post:
"Lots of guys who were bitter and/or quick to anger", yes, anything that is different to what they've experienced in life - I've been called "crazy, unhinged" for having pursued solo parenting by sperm donor - well, what was on offer at the time when I was dating were men who didn't want a family/ or we were just incompatible! They seem not to comprehend alternative routes/families come in different shapes and sizes.
"Very poor communication skills and lacked even basic etiquette" - yes, inability to engage with another person on a meaningful level, happy to keep answering questions you've asked them, hardly ever come up with original questions or ask you about your life, unable to carry on a conversation beyond the superficial day to day chit chat, overall poor emotional skills.
"Many liars whether it be height, age, occupation or marital status or all four." Yes - "misconstrued truth" once you've dug deeper into their lives.
"Profiles which detailed lots of hobbies with photos supporting this however in reality interests stretched to eating and watching TV. Football if I was lucky (watching not playing)." Yes - this nebulous hobby which turns out they do once in a blue moon, or something they did when younger.
And these were the men who initially had very interesting profiles/photos to begin with!