Simple and smart way to track portfolio ?

I was chatting with a friend and found out be has multiple investments in US and another country. Brokerage, 401k, CDs, HSA, some gold etc.. problem is, the amounts are not very significant, say <$10k per “account” He looked like he gave up on tracking and probably loosing potential gains, rebalancing etc.. Anyway, I only have a 401k and a little brokerage, so never had that problem myself. Do you have any recommendation to track such a portfolio, other than a good old excel sheet? I think on mi