Why is it at the expense of everyone else? By most of these wishes the rest of the group should be unaffected.
In which case, the wish is not world changing. But by being at the expense of everyone else, I mean that its mostly the DM having fun and exercising their creativity. The player isn't actually exercising their creativity unless the effect of the wish is reliable and predictable, and whether they enjoy an unpredictable wish or not, it's not the same as getting what you wanted.
Are wishes a regular thing in your games? I don't usually give out but one or two in a year and that's one or two total, not one or two per player.
No, they aren't very regular in my game, because I rarely play at high level where wishes become a necessary resource. The current party does have a 'wish' type item, that they've had since very low level (4th?) that provides a 1/day Limited Wish, but the item ('The Ancient Monkey Skull') is cursed (in that whomever uses it must make a saving throw or suffer a Bestow Curse type effect), so it doesn't get much use because it's a big gamble - at this level its basically a 50/50 shot of trading one bad problem for another one. It's kind of like knowing that your wish will be twisted, but you have a chance to have a not twisted wish if you make a saving throw. I generally would not make full wishes available until the group is above 10th level, because wish can easily become a 'Win Button' with regards to lesser problems.
At low level, I tend to provide powerful items with big drawbacks, and less powerful items that provide access to the sort 'recover from disaster' abilities that wish would otherwise have to be used to provide. There is no sense giving out a wish, when giving out access to a 2nd, 3rd, 4th or 5th level spell would provide the same benefit. There is no sense in having someone wish for strength, when you could just give out Gauntlets of Ogre Power or a Girdle of Giant Strength in the treasure to accomplish the same thing.
Beyond that, from low levels, the party has access to a lot of different mitigation effects in the mechanics that provide Protection from Bad Stuff. For example, every PC has Destiny Points, which are basically "Protection from Bad Luck", which they can use to reroll fumbles, failed saving throws, mitigate critical hits made on them, reroll Healing skill checks, and generally manipulate other
'Everything is on the Line' dice throws.
I also have Divine Intervention as a thing that does happen in the campaign and doesn't require DM fiat, so when a player is out of options they have a small chance of being able to successfully call on a deity they've piously served (or whom they've otherwise impressed) to intervene in life or death situations. This happens about once a year, and while a deities intervention isn't guaranteed to save your butt (the exact power level of the intervention depends on a dice throw, the PC's charisma, and the character's level), it generally does and has saved the lives of several PC's over the course of the campaign. One of the PC's has a 'The God's Really Like Me' advantage, and has received divine intervention twice, once in a spectacular fashion.