Is it practical to integrate turbofan or ramjet engines into an airliner wing?
The first turbofan, the Rolls-Royce Conway, had a bypass ratio of only 0.25 in order have a small enough diameter for placement in wing roots. It was initially planned for the V bombers and planned civilian derivatives of them. So yes, it is practical to place a turbofan engine in the wing, but comes at a cost:


Buried engine placement will shift the optimum to smaller bypass ratios, which reduces fuel efficiency.


Next, now your leading edge is occupied by an intake and cannot use any of the possible leading edge devices to increase lift at low speed for take-off or landing. The same goes for the trailing edge. The consequence is:


Buried engine placement will require a larger wing because the use of high-lift devices is not possible near the engines.


Larger wings weigh more and produce more drag in cruise. The last reason might be the most important: In operation, a podded engine is much easier to service and to repair than a buried one. The lower maintenance cost was the main driver for podded engines in the later members of the first generation of airliners (Boeing 707, DC-8, Convair 880).


Buried engine placement drives maintenance cost up.


There are fewer designs with ramjet engines, many of which never took to the air. Here, placement in the wing plane was mostly chosen to avoid thrust-related pitch moment changes. However, a ramjet is best used at high speed, and then you need to keep wing thickness down in order to reduce wave drag. Therefore, the engine placement cannot really be called buried anymore, but is closer to the buried than the podded variety.

The best example is the Lockheed D-21 drone pictured below (source). Since the aircraft is practically a ramjet with wings, the engine dominates the appearance.



Due to the high thrust needed for supersonic flight, supersonic aircraft keep their engines close to the wing and designs with podded engines like the Convair B-58 or the Myasishchyev M-50 were the exception. Stealth aircraft want to hide the hot exhaust and often use an overwing exhaust location which makes their engine placement also a buried one. You might argue that the engine of the Lockheed RQ-3 pictured below (source) is actually in the fuselage, but being a flying wing it does not have one:



The RQ-3 and similar designs like the Northrop B-2 clearly show that a turbofan engine location inside the wing is very practical indeed.