Travel power suppression was implemented by Cryptic/Paragon Studios to prevent "jousting" as a PvP strategy (the CoH equivalent to "bunny hopping" in PvP in other games).
It was a kludge then and it's a kludge now (still).
The foundational problem is that City of Heroes is fundamentally a PvE game, with only a vanishingly small minority of players engaged in PvP (despite plenty of game infrastructure having been built and dedicated to the purpose, starting with the oversized and essentially EMPTY Arena buildings). All attempts to "nudge" City of Heroes away from being a good PvE game into being a "fair" PvP game have foundered upon the fact that Player's are CRAFTY and CLEVER, able to leverage ANY advantage they are given in extraordinary (and unforeseen) ways.
One of the basic mismatches is that "games ought to be FAIR" in which opponents are (supposed to) have "equal opportunities of winning" ... such that the only deciding factor in combat ought to be Player Skill.
Of course, we all know that is NOT the case for how "fights to the death" work.
It might be how "fighting for sport" works, but not how "fights to the death" work.
SPORT fighting can have all kinds of RULES imposed on it to try and create a "level playing field" for the contest to take place.
DEATH fighting is all about MAXIMIZING ADVANTAGES such that your opponent cannot effectively fight back, rendering them PREY for the taking.
In medieval times, it was the armored knight on horseback with a lance who could kill any footman with a cavalry charge that was a Big Threat military strategy.
Counter? Massed longbow archery protected by pikemen for the "we hurt you, but you can't hurt us" response.
In WWI aviation, there was the entirely conventional strategy of Attacking Out Of The Sun, because if your opponent couldn't SEE you (until it was too late) the element of surprise and first strike would often win the day.
Counter? Massed formations of planes who would be able to cover each other in which some would survive the first strike from surprise.
In the past decade, in combat against non-state actors, the Improvised Explosive Device (IED) became something of a preferred tactic and strategy for surprise attacks.
Counter? Improved sensors, armor and training to be prepared for ambush.
So this cycle of Measure vs Countermeasure is hardly something new in the history of mankind.
Extending it into the realm of PvP with superpowers, there are going to be matchups where things get "decidedly unfair" in terms of tactics and strategies.
- Teleport Foe onto piles of Trip Mines being a classic (functionally a YOINK! onto a group of IEDs).
- Jousting via excessive speed being another.
- Hover Sniping thanks to extreme Range enhancement has been a favorite in PvE before it became a useful strategy in PvP.
- Mez vs Squishies being something that predates PvP, since it is a major threat in PvE already.
- "Juggling" via repeated Knock* powers that preclude opponents taking actions is another favorite.
My point being that PvP is
fundamentally and foundationally UNFAIR to those who participate in it. Trying to make PvP "fair" for everyone and anyone who engages in it is something of a Mug's Game.
So far, the only successful way to "balance" PvP games has been to essentially "lock" Players into a set of predefined classes of combatant (like how Team Fortress 2 or PUBG does it), rather than the BYOB (Bring Your Own
Beer Build) method of allowing Players to bring their PvE characters into PvP and EXPECTING everything to "balance" the same way that they do in PvE (where Players
mow down hundreds, if not thousands, of Foes between individual defeats).
The "demands" of PvP are NOT the same as the "demands" of PvE ... so of course any system that starts on a foundation of PvE will tend to founder when it needs to cater to the demands of PvP "fairness" in outcomes.
Gets worse when you realize that in PvP, NO ONE wants to engage in a "fair fight" ... because in PvP the motivation is to make the fights as UNFAIR AS POSSIBLE in order to extract an advantage over your opposition that they will find hard to counter.