Transaction fees can skyrocket anytime due to those garbage that are using bitcoin network but this not often and that is why whoever is DCAing should consider high transaction fees in future so that you don't end up using your profits in the long run to pay for high transaction fee.
This is why it is good that if you are DCAing when the transaction fee is very low just the way it is currently, you can consolidate y our small inputs into a big output for the future. You should make sure that the smallest input should be from $500 and above in one transaction to enable spend little fee in future.
On the other hand, if you are DCAing and the transaction fee become high, you can pile up your weekly DCA or monthly in your exchange account till it gets up to $500 and above excluding your transaction fee before sending it to your noncustodial wallet. Or you can leave it in the exchange till the fees goes back to normal, it is your choice. But save your bitcoin investment from high transaction fee depreciating too much of your profits in future.
I have experienced such a situation, and there is no problem with leaving it on the exchange for a while. because indeed high fees will be very burdensome for Bitcoin investors with DCA. there is still a risk but it will not be that high. moreover, if the situation of high transaction fees does not occur for a very long time, the situation will improve.
after that experience, I prefer not to make a purchase first when the situation is like that. temporarily saving the allocation will be more comfortable for me. but still saving funds to be ready to spend when the situation improves.
The reason why many folks have become interested in UTXO management in recent times is because there are likely going to continue to be high transaction fee circumstances in the future that could well undermine the value of the BTC that you hold, especially if you have a bunch of UTXOs with relatively low value. Let's say that you spent 4 years or longer buying $10 per week of BTC, and each time that you purchased the BTC, you withdrew that quantity to your private wallet, so maybe after 4 years you have more than 200 UTXOs, and sure perhaps the BTC price went up a lot during that time, so maybe you are going to be o.k. down the road, yet you cannot be sure about whether you are going to be o.k., and it could well be quite problematic to have so many UTXOs that are not very large as compared to whether you might have had been able to avoid those kind of situation.
Personally I am not very convinced about the idea of consolidating UTXOs as Frankolala had mentioned to be one of the potential solutions, yet consolidation could be one of the possible solutions if there are already problematic UTXOs. Another possible solution that Frankolala also mentioned is to just wait until the value gets above a certain size (whether it is dollar size or number of satoshis) in order to transfer larger UTXOs from exchanges to private wallets (addresses). Surely we do not want to keep large amounts of value on exchanges, yet it surely could be problematic to create a bunch of small UTXOs, too.. and each of us has to figure out ways to attempt to balance those kinds of matters, which sometimes may well involve using 3rd party custodians for some of the attempts to manage the size of our the UTXOs that we end up having in our private wallets/addresses.. We also may be better off to learn about wallets with coin control and maybe even learning about various ways to transact on second layers such as lightning network..