For the 50 HP argument, the problem is how heavily spread-based many SUM-on cards have been. We have normal Tapu Koko, Alolan-Ninetales-GX, Garchomp, Decidueye-GX, Frogs, Buzzwole-GX, Espeon-GX, Noivern-GX, etc., that can make it an easy prize waiting to be gotten - even if it isn't right away. Although I must admit, it probably won't be the biggest target.
Yes, spread damage (and bonus hits) have played a
significant role in recent times, and right now Buzzwole-GX is highly competitive, right? Let us take a step back for a moment; more than once I've had to explain to folks that a damage boost
only matters if triggers an effect, sets up for a combo, or reduces the number of turns it takes to score a KO. I brought that up because some folks have a hard time understanding why certain damage buffs are meaningless. This relates to the above situation in that we have to consider exactly what is happening in the above situations, and which of those decks are
currently competitive.
The short version is that in all cases, your opponent is giving something at least somewhat valuable up to score an effective OHKO against Dunsparce or it takes a
lot of incidental damage. If you're using Giant Water Shuriken to OHKO a Dunsparce on your Bench, it had better be for game (or an obvious lead up to it). The same if you're running Decidueye-GX and you use burn
three uses of Arrow Shot. If your opponent attacks three times in a row with Tapu Koko, that has to be a crazy combo deck or something has seriously gone wrong on your end. That does not mean it will
never matter in such matchups, but how often will your opponent take a key Prize by
not KOing Dunsparce while it is Active (which you
probably want) then later taking it out while it is on the Bench?
The main issue I have, though, is it can't do much after it uses its main attack. I mean, it can try to stall with paralysis, but it doesn't put much pressure against the opponent. At least with other leads, like Kangaskhan and Skarmory from older formats, they could do a decent amount of damage with their second attack, and had enough HP to not become major targets.
Dunsparce is not supposed to "do much" after it uses its main attack. I know some cards are great because they've got a solid fallback option after doing their main thing, but Tapu Lele-GX is great because of its Ability first, its solid stats second, and decent non-GX attack as a distant third. How do I know? Because Jirachi-EX was awesome with just the Ability; sure Jirachi-EX is Level Ball compliant, but that doesn't offset the other two.
What Kangaskhan and Skarmory are you talking about?
I wish this Dunsparce could have had 0-retreat, as it would then at least function as a pivot for other Pokemon to become active - and become less a pain to start with if you went first.
I'd rather the first turn rules didn't prohibit attacking but doing damage.
In other words, yes Dunsparce would be better if it had a free Retreat Cost, but it doesn't. I forget, are you not allowed to choose to go second? Yeah, it still matters as your opponent may win the coin toss and elect to go second, but I'm thinking this is a really,
really minor thing.
I know it seems like I'm nitpicking... I am! The thing is
I'm not alone. You're giving really
minor problems with the card. The main reason should be adequate; if you don't think an Energy attachment and giving up a Prize is worth searching out and Benching three Basics, that's good enough reason to think Dunsparce won't be worth it!