I know it is fruitless to have an actual conversation here, but oh well...
Pike is an assassin/support. Of course he has mobility, else he could not do his job. Of couse he has displacement as a form of CC, else he could not do his job. In any case he has much less mobility than many other assassins ( or at least it's more telegraphed ) in excange of camou%%%e, and the CC is slow to execute and easy to predict other than being his main tool.
Galio has two mobility skills, one that is arguabily not exactly useful for engaging since it's very slow and even pulls you back and one that is a global engagement tool. As a sort of tank/support ( at least ideally ) he needs mobility skills to get on the team, and displacements as a mean to have an impact. Arguabily displacements aren't much sensful to have if you can't use them to intercept other dashes but it is fine for him to have em too.
Taliyah is a mage, her only CC is one that allows her to disengage from enemies. That allows her to block champions that dash to her, since all her kit is sorta anti-mobility. Also yes, she roams, but hardly any other mage has such focus on roaming other than her so i don't see where is the deal.
Urgoth has a small displacement in form of an abismally small dash in order to have him some chance to actually reposition and use his kneeshots. Said displacement it's also a tool to force use the use of said kneeshots since the enemy won't walk there out of its volition. A good Urgoth can use most of kneeshots without displacement and still use it when necessary as a mean to force others, which i don't think it's any bad.
Als execute is useful for metas where tanks are oppressive. Laugh if you want, but spaghetti fight meta and games over 40 minutes were a thing.
"AoE" stun is weird on her kit and i agree, but why should that be a point on her post? Also, her dash has benn there since when she has been released and was taken in high consideration while reworking her.
I don't like Yasuo's displacement as a small tornado, but otherwise that is necessary for him to work. He was born as a sort of skirmisher bruiser ( which between patches has been evolved to be a lot of different things, included assassin ) so mobility for him was necessary, as well as damage denial and cc.
Ornn is a tank, so yet again he needs some small consideration as a form of mobility. Could use some stuns instead of knockups, but for being a tank it could be considered fine for him to have em.
Agree on Aatrox that displacement as there are for his Q are a bit off for me, but he needs mobility. He is not a pure tank and even a juggernaut needs some small repositioning. His dashes are abismally short and ar eused on conflict with his Q.
I don't see where is the problem for Rakan to have a charm, but he has a truly lot of dashes. But again, he is a support and usually supports don't get those.
Kayn displacement is only present in the bruiser/tank form, Rhaast, and is used to complement his role. he has many dashes indeed, but because yet again he is an assassin/skirmisher and assassins/skirmisher need those.
Also, i add that LoL Has already a whole lot of immobile champions - all the crapton of champions from season 1-3 have shallow spells that don't use dashes. Also, there have been champions that already had dashes and mobility for the same reasons stated as above. Why newer ones whould not have them?
Sometimes they pander too much on small dashes to get throught walls. Sometimes they forgot they can have usual CCs rather knockups or displacements and have them reserved to use them for tanks and deny mobility.
But i don't see why we sould not have again characters with dashes, especially since the next character to be reworked is the synonim of "dashes" in league since season 2. This is a crapload of list that has no sense whatsoever.