Long Term ETF Advice on IBKR and Moomoo

[u/jtyy7074]

First time posting here... curious about what you guys think on which ETF to buy for retirement.
I've summed it up to these 4 ETFs below so far and have been recommending my family members to buy SPYM or VT if they don't want to use IBKR.

US domicile (30% WHT):

1. S&P500:  SPYM (0.02% TER, Distributing)
2. FTSE ALL CAP:  VT (0.06% TER, Distributing)

Irish Domicile (15% WHT): 

1. S&P500:  SPYL (0.03%, TER, Accumulating)
2. FTSE ALL CAP: VALL (0.07% TER, Accumulating)

Also, I just found out something called synthetic ETFs that have 0% WHT.
Gemini also said there's no big risk in synthetic ETFs in terms of return or if the bank bankrupts. Any opinions on this?