Any realm that's been around a bit has enough gold to equip it's nobles with huge units. That's why you see everyone running around with 800CS units at minimum, with standing orders urging anyone with less to contact the council for gold. There is no risk of immense gold drain and even if there were it would be beneficial because there's too much gold. This has been discussed a ton already and is common knowledge on the forum.
What realms are you in where you have so much excess gold that it's more useful to send it to your family (which you said was useless) rather than spending it on your character, your unit or your realm?
I have a character with 1,500 gold who's actively fighting a war but makes more money than she spends on her unit. She even suicides her unit every so often for the honour gain, so that she can recruit an even bigger unit next time, but it's not enough. She offered someone gold once and was refused. She's handed out large sums for no reason. Doesn't make a dent. Occasions for philanthropy aren't frequent enough for them to matter very much, because everyone else is rich as well.
I have another character with 2,500 gold. His realm is at peace and everyone in it has huge units anyway, so there is nothing for him to spend it on.
I have a third character who had 1,500 gold until he sent 1k of it home and raised me to the wealth cap. Now I'm at the wealth cap, and he still has enough gold to purchase huge massive gargantuan units for eternity because his income is so high.
*I should note that none of my characters have particularly cushy positions. I've never been a duke or operated a region with more than 300 gold. My experience is nowhere near what truly rich characters must go through. I can only imagine how much gold dukes have on them. (probably 50,000)
