Your respective dads are probably my generation or at any rate mature enough to remember when undergravel filters were the only filter aside from the corner box filter.
And as the UG was "out of sight" it became very popular. And to be honest, it is a good filtration system, if one understands the pro's and con's and works within them.
When I bought my first "large" tank, a 90g, in 1995 I insisted on undergravel and I refused to be swayed away from this by the very knowledgeable store employee. Well, when i got my even larger tank a year later [how this hobby multiplies
] I did listen, and got an Eheim canister. Within a couple months, I went back and bought a second Eheim canister and pulled out the UG from the 90g.
Never looked back.
For my 29g I use a dual Elite sponge filter connected to an air pump. Another similar option if you don't want the noise of an air pump [I have three tanks connected to my pump, and they are in the fish room so noise is not an issue] is an internal "sponge" type filter like the Fluval "U" series. External canister filters are more expensive and not necessary on tanks under 50g, so the Fluval U works fine. I have one (or a similar type) on my 33g.