Phenibut easily replaces them in terms of withdrawal. The effects are better too, IMO, well, pregabalin is more intoxicating actually. But I like phenibut the most of the 3. However it will get you dependent on both gabapentinoids (VDCC ligands) and GABA-B agonists, so the withdrawals will be worse, but not sure if your intention is to dose it daily. PERSONALLY if I use it every 3 days I can get good effects every time. However since I've been addicted and withdrawn from it a few times, now I can't use it more than once a week or I get light withdrawals for a few days. It's hard to dose right, too much sucks and too little and you won't feel it. I wrote a usage guide which is in the trip reports forum and on Erowid under this name, that teaches you how to find your correct dose. Too much makes you feel like shit.
The above poster^^ is an example of it working differently for everyone. For me, phenibut lasts well over 24 hours, much longer than gabapentin or lyrica. It also doesn't even start taking full effect until 4 or 5 hours after you take it so you have to be patient. It's a more difficult drug to learn how to use properly, IMO. However, some people seem to get a much quicker and more acute effect that is over sooner and it produces hellish withdrawals in them and they don't like it. For what it's worth, everyone I know in real life has roughly the same experience with it as me, ie, lasts over a day, takes forever to come up, etc.
I have gotten stronger "druggy" euphoria from lyrica, but lyrica also makes me super sloppy. I get much stronger euphoria from phenibut than gabapentin (and I like gabapentin too). The thing I love about phenibut is that it makes me feel like super-sober, I am totally fearless socially, feel really motivated to do stuff, basically it feels like I'm having the best day ever, I want to talk to everyone, and I can do anything and do not appear or feel at all intoxicated. it's more like a stimulant than a GABAergic in that way, but is also relaxing even though it gives me energy and motivation. Except if I have too much, it make me sloppy and it's unpleasant. It's in my top 5, maybe even top 3, drugs of all time. But only when I dose it right (which I always do because I have using it for like 13 years off and on, I've taken it more than pretty much anything else except maybe weed and alcohol and opiates).