The original question seems ambiguous. This post answers one meaning. Locks with a traditional 'keyhole shape' keyhole made with warded mechanisms were generally of modest security, but with many different sizes, numerous skeleton keys would be needed to cope will any which might be met. Strong springs, and rust, mean picks need to be quite robust.
Modern door locks with a plurality of movable detainers (because not all are traditional lever mechanisms), and incorporating some pick-resisting features, such as widely used in Britain, are likely to be more secure than many door locks used in the USA.
The other possible meaning is the value of 'keyhole blocking locks', made to block the large keyholes of warded locks. Yes, most modern ones are small, with a pin tumbler mechanism, but unless one has a large selection of keys to try, of the correct keyway, they are a considerable obstacle. Their small size makes them awkward to pick.
In the past, the earliest versions used very high quality key mechanisms. The first one was invented by Samson Morden in 1841, using a Bramah lock. Soon afterwards, others were made using E. Cotterill's Climax mechanism.