Every house has two ages, one based on the year built and one called the "effective age". The effective age of a home will reflect its updates and maintenance. A well maintained, updated or remodeled home built in 1920 may have an effective age of just a few years.
A poorly built and maintained home built in 1990 may be older than its calendar age. Appraisers use this system in determining the final value of a home.
Most people that want vintage homes like this also desire the neighborhood in which the home resides. So, if the home is priced fair and solid and will enhance your happiness-Go for it.
So, get a good home inspector and don't think twice about whether to buy an "old" home.
One consideration is the purpose you are buying-If you are buying a home for your family to live in- you would want to give consideration to how long your family might be living in the home. The longer you plan to live there the more of a committment you should be willing to make to repairs and upgrades so the home gets healthier over time, therefore increases in value. If you are going to live in the residence for 7-10 or more years, before buying you should research which direction the community is going. Is it getting healthier, is it a neighborhood in decline.. Even then you will face a whole series of considerations once this information is established.
There is much more to say ancd consider, please look for an agent that has the ability to properly help you in reaching this decision. But I must say, your basic premise is very correct. But, not every buyer is capable of this kind of thought and consideration. I can only say you must be exceptional and thoughtful. I will also say your friends are only reflecting their own thoughts and limitations. I am sure they mean the best for you. But, they may not have the ability to think as deeply as you. I hope this has been helpful.
Personally I would prefer a home built prior to WW2 as they tend to have more character and detail that you can't find in newer homes. Plus they were built a whole lot better. If a home has been properly maintained there is no reason NOT to buy a 1920s home.
And as always, get it professionally inspected as part of your purchase.