I think this should be a primary thing in which anyone intending to hold BTC with whichever strategies must first put in place mostly when it involves valuable currency like BTC and holding for a long time no matter how small the investment should be a safe Wallet with private and strong security is meant to have been put in place. I think the custodial wallet has been announced severally on the forum even other wallet having similar feather and capable of holding BTC and give holder privacy as regards to security is there for holding.
I think knowledge in general is necessary and security as well this wallet is necessary because while adopting DCA as way if long time using wallet that give this security and confidence is very necessary I supported your point of view.
The problem with other is they got discourage immediately for seeing that they don't have big funds to conduct a long term hodl. They didn't think or explore some possibilities that they can increase their holdings by doing DCA or lump sum methods since even if they put small amount and if their target year before they release their investment to 4 - 10 years then provably their volume will be so big at that timeline. They just don't have enough confidence about it but if they gain enough experience for sure people will realize that everything they do especially for thinking about acquiring on any methods they are comfortable is rewarding in future. That's why for confused people about this maybe they should try to read up the suggestion of a lot since there are so many helpful pointers out there.
Also on wallet we select to use always prefer to have those wallets that we can safekeep our private keys and never use an exchange as alternative since we all know the risk is so high then the saying about not your keys not your coin is applicable on this.
Security of our funds is necessary so that we can assure that we have something to collect once our target years has been hit.