bAV Allianz perspective 100% subsidy vs. ETF

Hello everyone, I'm a little unsure about my company pension plan and would like to hear your opinion. My employer offers me direct insurance with Allianz (“Perspective”). I could either: pay €30 net/gross (deferred compensation) into the bAV myself and get €30 from the employer or simply put the €30 into an ETF (FTSE All World / MSCI World IMI). That means: either €60 into the bAV (30 + 30 AG) or €30 privately into an ETF. What concerns me a bit: Behind the