I am surprised and pleased that your VHS tapes are in such good condition. Tapes are notorious for wear and print through whereas modern solid state storage can fail but will not wear out.
My first thought is that you get a solid state drive, say about one Tb, and store everything on that. Then you can update more mobile storage devices such as SD cards or USB sticks whenever you want.
There is no perfect answer but two copies on your PC with a backup drive and working copies on solid state media should prove to be the most secure. My videos of my Grandchildren start in 2006 with my Granddaughter at three weeks of age.
The recording formats are standard for SD and HD so a video recorded onto a (for example) SD card will play on most devices. Again I suggest you buy a replay device that will cover all standard formats. Perhaps convert your VHS on your PC so it will download onto the current range of digital storage. As you are starting with VHS you could stay with HD as your highest format. I think 4K could be a step too far. If you are thinking of investing in a new camcorder then 4K would be OK because you can still output in HD from that camera.
I have a Panasonic Blu-Ray player. It has disk, SD card and USB ports plus an Ethernet connection. I currently store my videos on SD card with backup in my PC (two drives) The advantage is that the BR player is set up to playback from all the storage devices I currently have. Once I have videoed a sequence I download directly to my PC, edit the video and render it into a HD format then download to a SD card. I now have three copies, one on the PC drive, one on my backup drive and the working copy on a SD card. The SD card is then returned to the BR player for viewing.
I have boxes of old VHS tapes that the whole family enjoys but new technology has made making permanent playable videos painful and obsolete. I would love to buy a new video camera to continue preserving memories-but how? Now that they have done away with tapes that you can keep and store. Everyone says the Cloud- but the 5 Gig that they all give free fills up amazing fast. After that -I refuse to “rent” cloud space monthly. If I could buy a terabyte and it was mine forever that would be one thing. But by making you pay monthly- what happens when you stop paying- you lose access? I don’t know anyone that has lost video and been able to log into a cloud account and actually find, see and play the media. Even if you could they are making you pay monthly FOREVER. Option 2 -memory cards. PROBLEM. when it it formatted on a device and you try to play it on a PC- the first thing it wants to do is reformat the card- BOOM all data lost. After tapes I tried copying to DVD. Again the DVD is formatted to the device it was recorded on- when that machine is gone - so are the videos- it won’t play on a different device. It is just so painful - I ended up just giving up after my kids grew up- like a lot of other people. We all now upload to social media like facebook. But what happens if Facebook goes the way of MySpace in the future- all the photos etc are gone. Is there any way to take a modern camcorder and EASILY produce and preserve a video that can just be plugged in and played IN ANY MACHINE like the old VHS tapes- with out risk of it being reformatted? Photos and Facebook are nice but nothing is like being able to put in a old VHS tape and see and HEAR parents that have passed or seeing and HEARING your children when they are small. From what I see - people are not preserving video like they did before the whole process became painful. Now we just pull out our mobile phone and but then upgrade and turn in those phones every 2 yrs- losing what we have saved.