Yes, but so what?
Most (all?) common law countries follow an adversarial system, where the court is a referee. Parties run their pre-trial investigation and choose their witnesses with a relatively large degree of autonomy. As such, an expert witness is clearly identified as the witness that one of the sides decided to call. The other side will have an opportunity for cross-examination, to point flaws in their testimony or cast doubt on the expert’s credibility.
Davislor’s answer describes criminal trials. In such instances, one party (the state or federal government) has essentially unlimited resources but bears the burden of proof. By contrast, the defendant usually does not have the resources to put up an opposing expert, but might still decide to try to go to trial for a host of reasons. In that situation, the local "expert witness industry" in topics related to criminal cases is hired disproportionately by the state/feds.
Compare to civil cases. Going to trial in a civil case is an expensive proposition, but even more so when one has to pay experts. Therefore, in the fraction of cases that go to trial, the plaintiff expects that the defendant can pay a large award. In turn, that means the defendant can afford to call expert witnesses of their own.
An extreme example would be Oracle vs. Google, where Google put up an expert witness for matters that could clearly have been explained by some of their internal staff. Presumably, this was done to impress the jury with an "impartial" witness.
Of course, that approach to expert testimony is considered unfair by some. Detractors of the "battle of experts" say that the system favors rich parties who can pay famous experts which will impress the judge/jury, even though the opposing party’s expert might have the better side of the scientific debate. That criticism overlaps with the more general criticism that common-law/adversarial systems are alledgedly more biased towards the rich parties than civil-law/inquisitorial systems.
Another approach: civil law
France is a civil-law system with an inquisitorial system. For criminal cases, the judge(s) is (are) running the show. Experts are called from a local list maintained by the court, and paid by the courts (rather than either party).
The risk of bias in such a scheme is fairly low, because the expert is not compensated by either party. However, courts are notoriously underfunded and experts are paid late and not much, which certainly does not attract the best talent. Another problem is that expert testimony becomes much harder to challenge, as hiring a "counter-expert" is not feasible.
While (to my knowledge) bite-mark analysis never made it into French courts, another pseudoscience did. Psychoanalysis (the Freudian stuff) is by and large considered a pseudoscience by psychiatrists/psychologists. However, many court experts are psychoanalysts, who make it to the expert list thanks to a psychology degree, but use the Freudian (pseudoscientific) analysis when performing their services. There is no Daubert motion to be done to exclude such expert testimony, and that testimony is often written (the French procedure does not require all witnesses to testify orally), so there is not much a party can do to contest it (lawyer: "it’s pseudoscience!" judge: "from our court expert? I don’t think so"). There is an ongoing debate to purge those from the expert list
(link in French to an advocacy piece).
The interested reader might want to consult Comparative Study on Expert Witnesses in Court Proceedings, a freely-accessible 2009 report commissioned by the Turkish judiciary, which compares the status of experts across France, Germany, Italy, and the United States in much detail (I only skimmed the executive summary).