Well look at the beginning stats of the races.
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So Iksars have 10 more STR, 5-15 less CHA, and WIS/DEX/AGI are basically useless. So from these stats there isn't really much reason to pick one race or the other.
All races have basically the same STA, 65/70/75. None have a clear winner in this stat. 5 STA means 12 HP at level 60. Such a minuscule value, not going to make much difference ever.
Iksars have 85 INT, which is 23 behind gnome, 24 behind DE and 32 behind Erudite. Basically what this means is an Iksar will need to devote most of their creation stats to INT. while the other races can get away with either stacking INT or pouring theirs into STA. (at level 60, the 25 STA will amount to 60 HP)
At level 60 in Velious most mains will cap out their primary stat (INT) with typical gearing, regardless of base stat. A non-Iksar possibly can focus on HP gear before an Iksar can if they care about capping it. However most good HP/Mana pieces for Necros in Velious also come with INT on them, so a high INT player will end up wasting a lot of it by going over cap.
So the choice is, as a non-Iksar you may dump 25 into STA and get an extra 60 HP later on, or dump it into INT, and sit around 130-140 base INT, allowing you to focus on HP/Mana gear once you cap out (125-115 item/spell INT).
Or... Go Iksar, get gear to equalize the beginning stat difference, and have a racial ability that stacks with everything and cannot be replaced.
Everyone makes mistakes in game, gets hit, needs and FD. Having regen helps in these cases, helps when you're twitching on raids, helps you root rot or fear kite more efficiently, helps you be more efficient in groups. There really is no argument for picking a non-Iksar beyond fashion/you made it before Kunark/you made your classic character.
Regen matters whenever your health isn't 100%, which when you're liching is almost always.